"covering," Old English hod "a hood, soft covering for the head" (usually extending over the back of the neck and often attached to a garment worn about the body), from Proto-Germanic *hōd- (source also of Old Saxon, Old Frisian hod "hood," Middle Dutch hoet, Dutch hoed "hat," Old High German huot "helmet, hat," German Hut "hat," Old Frisian hode "guard, protection"), which is of uncertain etymology, perhaps from PIE *kadh- "to cover" (see hat).
Modern spelling is early 1400s to indicate a "long" vowel, which is no longer pronounced as such. Used for hood-like things or animal parts from 17c. Meaning "Foldable or removable cover for a carriage to protect the occupants" is from 1826; meaning "sunshade of a baby-carriage" is by 1866. Meaning "hinged cover for an automobile engine" attested by 1905 (in U.K. generally called a bonnet). Little Red Riding Hood (1729) translates Charles Perrault's Petit Chaperon Rouge ("Contes du Temps Passé" 1697).
Old English etan (class V strong verb; past tense æt, past participle eten) "to consume food, devour, consume," from Proto-Germanic *etan (source also of 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."
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.
"a hat," 1520s, from French chapeau (Old French capel, 12c.) "hat," from Vulgar Latin *cappellus, from Late Latin capellum (also source of Italian cappello, Spanish capelo, Portuguese chapeo), diminutive of cappa (see cap (n.)). Especially a hat forming part of an official costume or uniform.
"garland or wreath for the head," late 14c., from Old French chapelet (Old North French capelet) "garland, rosary," properly "a small hat," diminutive of chape, chapeau "head-dress, hood, hat" (see chapeau).
"clasp, button, etc. used to secure the cock of a hat," hence "any knot or badge worn on a hat," especially as a sign of political adherence, 1709, earlier cockard (1650s), from French cocarde (16c.), fem. of cocard (Old French cocart) "foolishly proud, cocky," as a noun, "idiot, fool;" an allusive extension from coq (see cock (n.1)).
