日本語版

Research note 025 — 2026-09-04

The Map of "Bitter" — From One Word to East and West

When laying out a map, one method shows every point first and explains afterward; another sets a foot down in one place and walks outward from there. This note takes the second approach. The starting point is the Japanese word 「苦い」 (nigai, in translation: "bitter"). From there it reads through dictionaries eastward and westward, meets along the way a different kind of map — the terminology systems of standards bodies and of beer, coffee, and wine — passes through a place where a sensation itself gets confused with another, and finally arrives at a small margin where only a word with its degree weakened carries a value of its own.

What this page establishes

• The Japanese word 「苦い」 (nigai) carries, as separate dictionary senses, both a taste meaning and an emotional meaning of being painful and hard to bear.
• English bitter has been confirmed, in dictionary etymology entries, to derive from a root meaning "to bite," while Greek πικρός (pikros) has its original sense confirmed as "pointed, sharp."
• Wine's mouth-feel wheel has been confirmed to carry no independent "Bitter" item, while beer's and coffee's sensory vocabularies each place bitterness as an independent class or definition in their own terminology systems (for beer, the number of classes and the position of bitterness have been checked only up to the abstract of the official edition, so this is preliminary).
• The phenomenon of confusing sourness with bitterness has been reported in both English and Spanish, but how general it is across other languages has not yet been confirmed.

The starting point — inside one word, nigai

The Digital Daijisen defines the first sense of 「苦い」 (nigai, in translation: "bitter") as 『舌を刺激し、口がゆがむような嫌な味である。』 (in translation: "an unpleasant taste that stimulates the tongue and makes the mouth pucker"). Already, inside a definition meant to describe the taste itself, an evaluation — "unpleasant" — has been built in.

The same word's third sense moves away from taste and extends to 『つらくて苦しい。その事を考えたり思い出したりするのも嫌である。』 (in translation: "painful and hard to bear; one dislikes even thinking of or remembering it"). Already, within the single word chosen as the starting point, two paths — taste and feeling — stand prepared.

Before taking a first step, there is already a small history underfoot. For the noun 「苦み」 (nigami, in translation: "bitterness"), the same dictionary notes, as a supplementary remark, 『「味」は当て字。』 (in translation: "the kanji mi [\"taste\"] is an ateji [a phonetic substitute character]"). Even the starting point of the map does not have a single, unified origin.

Eastward — ku, a plant's name, and how degree becomes its own word

The Shuowen Jiezi, as quoted by Hanyu Zidian (zdic.net) under the Chinese character 「苦」 (ku, in translation: "bitter"), records 『大苦，苓也。』 (in translation: "dà kǔ [great bitterness] is líng [a plant name]."). The character's original meaning, it turns out, was not a quality of taste but the name of a plant.

From there, the meaning extends to hardship. For the compound 「甘苦」 (gānkǔ), the Ministry of Education's Revised Mandarin Chinese Dictionary gives the sense 『比喻處境的順逆與苦樂。』 (in translation: "a metaphor for favorable or adverse circumstances, and hardship or joy"), with an example quoted from the Records of the Grand Historian (Shiji): 『燕王弔死問孤，與百姓同甘苦。』 (in translation: "the King of Yan mourned the dead and inquired after orphans, sharing gānkǔ [hardship and joy] with the common people"). A character that began as a plant's name has been carried all the way to a scene of a ruler sharing hardship and joy with the people.

Korean's map has a different shape again. The Standard Korean Language Dictionary defines 「쓰다」 (sseuda, in translation: "bitter") as 『혀로 느끼는 맛이 한약이나 소태, 씀바귀의 맛과 같다.』 (in translation: "the taste sensed by the tongue is the same as the taste of herbal medicine, sotae [a bitter wood], or sseumbagwi [a bitter lettuce]") — defined through specific things and plants.

Yet this same dictionary also gives a headword of its own to the strength of bitterness itself. The definition of 「씁쓸하다」 (sseupsseulhada) is the single sentence 『조금 쓰다.』 (in translation: "a little bitter"), standing as its sole sense entry. A difference of degree here qualifies not as a derivative turn of phrase but as an independent headword.

Thai walks a still different road. The Royal Institute of Thailand's dictionary outlines 「ขม」 (khom, in translation: "bitter") as 『รสอย่างหนึ่งอย่างรสสะเดาหรือบอระเพ็ด.』 (in translation: "a taste like the taste of sadao [neem] or bora phet [a bitter vine]") — traced through two plant names.

And 「ขมขื่น」 (khomkheun), a word derived from the word for the taste, lands somewhere apart from taste altogether. The same dictionary explains it as 『รู้สึกชํ้าใจแต่ฝืนไว้ เพราะไม่สามารถแสดงออกมาได้』 (in translation: "enduring a hurt feeling because one cannot show it outwardly"). Bitterness has become the name for holding in a pain one cannot show.

Westward — biting, sharpness, and the children of Latin

Folding the map back westward, the ground beneath the starting point changes. Perseus's Lewis & Short A Latin Dictionary presents Latin amarus through the example 『"absinthi latex,"..."sensus...judicat dulce, amarum"』 (in translation: citing "absinthi latex" ["the juice of wormwood"] ... "sensus...judicat dulce, amarum" ["the senses judge what is sweet, what is bitter"]), fixing its literal sense as the antonym of dulcis ("sweet"). In the place where the East had a plant's name, the West too turns up the same plant — wormwood.

English bitter's etymology, however, begins not with a plant but with an action. Merriam-Webster's etymology entry records it as 『derivatives from the base of *bītan- "to bite"』 (in translation: "derivatives from the base meaning 'to bite'").

Greek πικρός (pikros) begins in yet another way. The original sense given by the LSJ (Liddell-Scott-Jones) definition is 『prop. A. pointed, sharp, keen』 (in translation: "properly, pointed, sharp, keen") — a word that rose first to describe an arrow or a thorn, before its meaning extended out to the pungent sensation of taste.

Latin amarus is also one parent on this western side of the map. CNRTL (TLFi) traces the etymology of French amer to 『Du lat. amarus, attesté au sens propre dep. Ennius...; au sens fig. dep. Rhét. Her.』 (in translation: "from Lat. amarus, attested in its literal sense from Ennius on; in its figurative sense from the Rhetorica ad Herennium on"), and records its first written attestation at the sense dated 1174.

Italian amaro shares the same parent. The Treccani Vocabolario gives, immediately after the headword, only the note 『[lat. amarus]』 (in translation: "derived from Latin amarus"). Where French tells the story through centuries of accumulated citations, Italian settles it in a single set of brackets — even with the same ancestor, how much a dictionary says about etymology differs dictionary by dictionary.

And bitter's metaphor stretches in a different direction from the East's "sharing hardship together." Separately from its taste sense, Merriam-Webster records the senses 『distasteful or distressing to the mind : GALLING』 and 『caused by or expressive of severe pain, grief, or regret』. Bitterness here is not something shared, but the name for a pain or regret that one person carries alone.

An enclave on the map — standards, beer, coffee, and wine

Outside dictionaries, too, there is a map that names bitterness. The international standard ISO 5492 positions bitterness as one of the basic tastes: 『any one of the distinctive tastes: acid/sour, bitter, salty, sweet, umami』.

The same standard defines bitterness itself as 『basic taste produced by dilute aqueous solutions of various substances such as quinine or caffeine』, with no word of feeling included. Where the eastern and western dictionaries raised their words from plants or actions, the standard raises its word from the concentration of a reference substance.

In the main text of a 1982 paper, the international beer flavor terminology system published in 1979 is organized as a diagram of 14 classes and 44 first-tier terms, and within it, bitterness is placed as its own class, class 12, "BITTER." The official edition of that paper has been checked only up to its abstract, however, and the abstract gives neither the number of classes nor the position of bitterness, so this is treated as a preliminary record.

In coffee's sensory vocabulary, too, bitterness holds an independent place. World Coffee Research's Sensory Lexicon defines "BITTER" as 『The fundamental taste factor associated with a caffeine solution.』

Cross over, though, to the wheel that organizes wine's mouth-feel, and bitterness disappears from the map. The body text frames red wine's mouth-feel as a composite of acidity, sweetness, bitterness, and more, yet the outer ring of terms actually assembled has no independent item called "Bitter." Bitterness appears only inside the definitions of "hard" and "sappy," both derivatives of astringency.

Where the map gets confused — sour and bitter overlap

The map also has places where a traveler loses their bearings. One study's abstract reports that, alongside the confusion of sour and bitter in English, a confusion between ácido ("sour") and amargo ("bitter") was also observed in Spanish.

Another study's abstract reports that English speakers tended to use a four-way classification of "sweet," "sour," "salty," and "bitter," while Japanese speakers tended to add to these the label "Ajinomoto," referring to the taste of monosodium glutamate. Where the line gets drawn — into how many words the basic tastes get divided — is itself drawn in a different place from map to map.

A still broader survey shows that how easily taste as a whole sense can be put into words differs by language itself. In one language, taste falls among the senses that are harder to name; in another, a different ranking shows up — described not as better or worse, but as a different placement from map to map.

Value in the margins of the map — what only a weakened word carries

The core sense sitting at the center of the map was, in many places, "an unpleasant taste." Yet a word that softens that core sense just slightly can come to carry a different value. The Digital Daijisen defines 「ほろ苦い」 (horonigai, in translation: "slightly bitter") as 『ちょっと苦みがある。なんとなく苦い。』 (in translation: "has a slight bitterness; somewhat bitter"), and alongside the example 「ほろ苦い味わい」 (in translation: "a horonigai flavor"), it lists a non-negative usage: 「ほろ苦い初恋の思い出」 (in translation: "a horonigai memory of first love").

Italian amarognolo takes the same shape. The Treccani dictionary defines it as 『Di sapore amaro ma non sgradito』 (in translation: "having a bitter taste but not unpleasant"), and gives as its example 『mi piace l'amarognolo di questo liquore』 (in translation: "I like the amarognolo [mild bitterness] of this liqueur") — favorability built directly into the dictionary's own example.

Articles on Chinese-language tea culture soften bitterness the same way. In the context of explaining 回甘 (huigan) and 回甜 (huitian), the phrase used is 『入口时清甜微苦涩』 (in translation: "on first taste it is lightly sweet with a slight bitterness and astringency") — the single character 微 ("slightly") shaves down the strength of the bitterness, turning it into a taste the drinker can meet without bracing for it.

On Korean's map, this softening is recorded as a family of vocabulary. The Standard Korean Language Dictionary defines 「쓰다」 (sseuda) as the basic sense of bitterness, while the definitions of both 「씁쓸하다」 (sseupsseulhada) and 「쌉싸름하다」 (ssapssareumhada) include the degree-weakening word 『조금』 (in translation: "a little"), which the basic sense's definition does not. Weakening the degree is treated here as a distinction worth its own headword.

The definition of that second headword, 「쌉싸름하다」, is 『조금 쓴 맛이 있는 듯하다.』 (in translation: "seems to have a slightly bitter taste"), with 「쌉싸래하다」 given alongside it as a synonym. In this one corner reserved for weak bitterness alone, more than one word already lives.

And 回甘 (huigan), as spoken of in Chinese tea tasting, measures weakness not by degree but by time. A slight bitterness and astringency felt at first taste gives way, as time passes, to a sweetness that becomes dominant, ending in a sweet aftertaste — in this same corner of the map sits not only a weakening of strength, but a weakening across time.

Places the map never reached

The map breaks off here. Places that could not be reached — an official Vietnamese-language dictionary, Japanese sensory-vocabulary glossaries for tea, miso, soy sauce, coffee, and the like, or the body text of a source itself — have been left blank for now. A blank does not mean nothing is there; it is left as room for someone to bring material to, later.

Frequently asked

What is the etymology of bitter (苦い)?

English bitter, according to Merriam-Webster's etymology entry, traces back to Old English biter, and further back to a Proto-Germanic word built on a root meaning "to bite." Latin amarus, on the other hand, is defined, as a matter of sensation, as the antonym of "sweet," citing the juice of wormwood as its example. Greek πικρός (pikros) differs again: its original sense, as the dictionary definition records, was "pointed, sharp" — a word that rose to describe an arrow or a thorn before extending to the sense of a bitter sting. Even for the same word "bitter," the sensation or image that served as the starting point differs by language.

Why does bitterness also carry the sense of "hard to bear"?

The Japanese word 「苦い」 (nigai) is defined by the Digital Daijisen as carrying, alongside its taste sense, the further sense of "painful and hard to bear." In Chinese too, 「苦」 (ku) has a plant's name as its original meaning, yet in the compound 「甘苦」 (gānkǔ) it is used as a word that metaphorically expresses favorable or adverse circumstances, hardship or joy. English bitter also has, on record in the dictionary, a sense pointing to what is unpleasant and distressing to the mind, and a sense deriving from severe pain, grief, or regret. The sense that links taste-bitterness to emotional hardship is recorded separately, in the dictionaries of more than one language.

What is not known

• How the bitterness class in beer's terminology system is actually defined in relation to specific compounds or concentrations has not been confirmed as far as the body text of the 1979 original paper.
• Whether the reason wine's mouth-feel wheel has no item for bitterness is confusion with astringency, or a separate design decision, cannot be determined within the scope of this material.
• Whether the confusion of sourness and bitterness also occurs in languages other than English and Spanish has not yet been confirmed.
• Whether a weakened bitterness expression such as 「微苦」 (wēikǔ) is established as an independent headword in Chinese dictionaries has not been confirmed.
• Whether the language-by-language difference in how easily taste as a whole sense can be named applies directly to bitterness as an individual taste cannot be read out separately from the material.

Related: nigai (Japanese) / ku (Chinese) / sseuda (Korean) / khom (Thai) / amarus (Latin) / bitter (English) / pikros (Greek) / amer (French) / amaro (Italian) / ISO 5492 / the beer flavor wheel / the coffee sensory lexicon / the wine mouth-feel wheel / horonigai (gently bitter) / huigan
Related topic hub: The Words for Bitterness
Related research note: Where "Bitter" Becomes a Compliment / What separates nigai from horonigai?
Source ledger: the source ledger