eatyoudaoicibaDictYouDict[eat 词源字典]
eat: [OE] Eat is a very ancient and basic verb. It goes back to Indo-European *ed- ‘eat’ (distant ancestor of English tooth), which produced the basic word for ‘eat’ in most European languages, apart from French, Italian, Romanian, and the Celtic languages: Greek édein, for example, Latin edere (source of English comestible [15], from Latin comedere ‘eat up’, and of obese [17]), and Russian jest’. Its Germanic descendant was *etan (ultimate source of English etch), which produced German essen, Dutch eten, Swedish öta, and English eat (and also lies behind English fret).
=> comestible, etch, fret, obese, tooth[eat etymology, eat origin, 英语词源]
eat (v.)youdaoicibaDictYouDict
Old English etan (class V strong verb; past tense æt, past participle eten) "to consume food, devour, consume," from Proto-Germanic *etan (cognates: Old Frisian ita, Old Saxon etan, Middle Dutch eten, Dutch eten, Old High German ezzan, German essen, Old Norse eta, Gothic itan), from PIE root *ed- "to eat" (see edible).

Transferred sense of "corrode, wear away, consume, waste" is from 1550s. Meaning "to preoccupy, engross" (as in what's eating you?) first recorded 1893. Slang sexual sense of "do cunnilingus on" is first recorded 1927. The slang phrase eat one's words "retract, take back what one has uttered" is from 1570s; to eat one's heart out is from 1590s; for eat one's hat, see hat. Eat-in (adj.) in reference to kitchens is from 1955. To eat out "dine away from home" is from 1930.