Etymology
1. late O.E.
cepan "to seize, hold," also "to observe," from P.Gmc.
*kopijanan, but with no certain connection to other languages. It possibly is related to O.E.
capian "to look," from P.Gmc.
*kap- (
cepan was used c.1000 to render L.
observare), which would make the basic sense "to keep an eye on."
"The word prob. belongs primarily to the vulgar and non-literary stratum of the language; but it comes up suddenly into literary use c.1000, and that in many senses, indicating considerable previous development." [OED]
Meaning "financially support and privately control" (usually in ref. to mistresses) is from 1560. The noun meaning "innermost stronghold of a tower" is from 1586, perhaps a translation of It.
tenazza, with a notion of "that which keeps" (someone or something); the sense of "food required to keep a person or animal" is attested from 1801.
Keepsake is first recorded 1790, on model of
namesake; thus an object
kept for the
sake of the giver.
For keeps "completely, for good" is Amer.Eng. colloquial, from 1861.
Keeper "one who has charge of some person or thing, warden" is from c.1300; sense of "one who carries on some business" is from c.1440.
2. From Middle English kepen (“to keep, guard, look after, watch”), from Old English cēpan (“to seize, hold, observe”), from Proto-West Germanic *kōpijan, from Proto-Germanic *kōpijaną (“to look, heed, watch, observe”) (compare West Frisian kypje (“to look”)), from Proto-Indo-European *ǵab-, *ǵāb- (“to look after”) (compare Lithuanian žẽbti (“to eat reluctantly”), Russian забо́та (zabóta, “care, worry”)).
3. The dialectal sense of the verb meaning “to put back” or “put away” may be analyzed as a semantic loan from a local language—compare Welsh cadw and Mandarin 收 (shōu). See: Middle English '
kepen', Proto-Germanic '
*kōpijaną'.