• (British) IPA: /ˈbɪtə/, [ˈbɪtʰə], [ˈbɪʔə]
• (GA) IPA: /ˈbɪtəɹ/, [ˈbɪɾɚ]

bitter (comparative bitterer, superlative bitterest)

1. Having an acrid taste (usually from a basic substance).

   The coffee tasted bitter.

   • 1907, Robert William Chambers, chapter III, in The Younger Set, New York, N.Y.: D. Appleton & Company, OCLC 24962326 ↗:

     Long after his cigar burnt bitter, he sat with eyes fixed on the blaze. When the flames at last began to flicker and subside, his lids fluttered, then drooped; but he had lost all reckoning of time when he opened them again to find Miss Erroll in furs and ball-gown kneeling on the hearth […].

   • 2018 May 16, Adam Rogers, Wired, "The Fundamental Nihilism of Yanny vs. Laurel ↗":

     A few types of molecules get sensed by receptors on the tongue. Protons coming off of acids ping receptors for "sour." Sugars get received as "sweet." Bitter, salty, and the proteinaceous flavor umami all set off their own neural cascades.

2. Harsh, piercing or stinging.
   • 1999, Neil Gaiman, Stardust, p.31 (Perennial paperback edition)

     It was at the end of February, […] when the world was cold, and a bitter wind howled down the moors […].

3. Hateful or hostile.

   They're bitter enemies.

   • 1749, Henry Fielding, The History of Tom Jones, a Foundling

     He inveighed against the folly of making oneself liable for the debts of others; vented many bitter execrations against the brother; and concluded with wishing something could be done for the unfortunate family.

   • 1611, The Holy Bible, […] (King James Version), imprinted at London: By Robert Barker, […], OCLC 964384981 ↗, Colossians 3:19 ↗:

     Husbands, love your wives, and be not bitter against them.

4. Cynical and resentful.

   I've been bitter ever since that defeat.

• (cynical and resentful) jaded

• (cynical and resentful) optimistic

• French: amer
• German: bitter; (in a pleasant way, as in beer) herb
• Italian: amaro, amara
• Portuguese: amargo
• Russian: го́рький
• Spanish: amargo

• French: dur, sévère
• German: bitter, arg, harsch, hart
• Italian: aspro, (of weather) gelido
• Portuguese: agudo, penetrante
• Russian: го́рький

• French: haineux, haïssable, odieux, (hostile) hostile
• German: erbittert, verhasst, hässlich, (hostile) feindlich
• Portuguese: encarniçado
• Russian: зло́бный

• French: amer
• German: verbittert
• Portuguese: amargurado
• Russian: злой
• Spanish: amargado

bitter

1. (usually in the plural bitters) A liquid or powder, made from bitter herbs, used in mixed drinks or as a tonic.
   • 1773, Oliver Goldsmith, She Stoops to Conquer

     Thus I begin: "All is not gold that glitters,

     "Pleasure seems sweet, but proves a glass of bitters.

2. A type of beer heavily flavored with hops.
3. (nautical) A turn of a cable about the bitts.

• (beer) English pale ale, EPA

bitter (bitters, present participle bittering; past and past participle bittered)

1. To make bitter.

bitter (plural bitters)

1. (computing, informal, in combination) A hardware system whose architecture is based around units of the specified number of bits (binary digits).
   • 1983, Computerworld (volume 17, number 49, page 21)

     However, 16-bitters are far more expensive than the 8-bit variety. And, unfortunately, have only a handful of business applications software packages that really take advantage of them.

   • 1984, Electronic Business (volume 10, page 154)

     The company believes that the 32-bit market will almost equal that of 16-bitters by the end of the decade. Chip maker Zilog Inc., not a major player in the 16-bit arena, is even more bullish about 32-bitters as it readies its own version for market.