What is the Latin word for eager?

The usual Latin words for “eager” are cupidus, avidus, appetō; also studiōsus, incendō, flagrō. The right choice depends on the sense; see the distinctions below.

English → Latin

“eager” in Latin

cupiduseager, desirous, passionate, fond (+ genitive or + in ablative); greedy, covetous; wanton, lecherous avidusgreedy, avaricious, covetous; eager, enthusiastic, desiring, desirous; lustful, passionate; eager, hungry, voracious, gl appetōto strive for, reach after (something), try to get; to attack, fall or seize upon, assault, assail; to approach, draw ni studiōsuseager, zealous, fond, assiduous; anxious; studious incendōto set on fire, burn, kindle; to heat, make hot, scorch; to light up with fire, make a fire upon flagrōto burn, blaze caliduswarm, hot; fiery, fierce, vehement; spirited, impassioned ārdeōto burn (be consumed by fire); to glow; to glisten with a feature, usually with a colour ferveōto be hot; to burn; to boil; seethe, foam fervidusboiling, seething; glowing; boiling hot; fiery; fervid

The English word eager itself goes back to Latin ācer, through ācrus.

Riddle & Arnold A Copious and Critical English–Latin Lexicon, 1864

eager

With an object expressed (eager for, after, etc.), cupidus: avidus (stronger than cupidus): appetens: studiosus (all, alicujus rei): desiderio alicujus rei captus (Terentianus), incensus, flagrans (Cic.). Eager for contention, cupidus contentions (Cic.); in the pursuit of truth, cupidus veritatis; in the pursuit of praise, glory, avidus laudis, gloriae; appetens gloriae (Cic.): to be eager after (or in pursuit of) anything, cupere, concupiscere, avere, appetere, desiderare aliquid; imminere alicui rei or ad aliquam rem; (stronger) cupiditate alicujus rei rapi, trahi, ardere, flagrare, inflammatum esse; sitire aliquid; studiosum esse alicujus rei; versari in cupiditate alicujus rei; tenet me cupiditas alicujus rei; avide affectum esse de re. I am eager for revenge, ardet animus ad ulciscendum. I am becoming eager after anything, injicitur mihi alicujus rei cupiditas (Cic.): to be becoming or growing eager, cupiditate, desiderio incendi: to make anybody eager, cupiditate aliquem incendere, afficere; in cupiditatem irnpellere. All being eager to fight, omnibus ad pugnam intentis.

Ardent, impetuous, calidus; ardens; fervens or fervidus; vehemens: acer. An eager temper, ingenium ardens or fervidum. An eager patriot, civis acerrimus: eager prayers, precum constantia (Tac., Germ. 8, 1).

Sharp, acid, Vid:

Keen, cold, Vid.

Quick answer

What is the Latin word for eager?: The usual Latin words for “eager” are cupidus, avidus, appetō; also studiōsus, incendō, flagrō. The right choice depends on the sense; see the distinctions below.

Entry from J. E. Riddle & T. K. Arnold, A Copious and Critical English–Latin Lexicon (rev. C. Anthon, New York: Harper, 1864), digitised by Fergus J. P. Walsh, CC BY-SA 4.0; Latin markup adapted by latindictionary.co.