Chicken
Old English cīcen, cȳcen, of Germanic origin; related to Dutch kieken and German Küchlein, and probably also to cock1.
wiktionary
From Middle English chiken (also as chike > English chick), from Old English ċicen, ċycen(“chicken”), of uncertain origin. Possibly from Proto-West Germanic *kiukīn(“chicken”), or alternatively from Proto-West Germanic *kukkīn, equivalent to cock + -en. Compare North Frisian schückling(“chicken”), Saterland Frisian Sjuuken(“chicken”), Dutch kuiken(“ chick, chicken”), German Low German Küken(“chick”), whence German Küken(“chick”), (elevated, obsolete)German Küchlein(“chick”) and Old Norse kjúklingr(“chicken”).
Shortening of chicken out.
From chick + -en(plural ending).
etymonline
chicken (n.)
Old English cicen (plural cicenu) "young of the domestic hen, the young of any bird;" by early Middle English, "any chicken," regardless of age, from Proto-Germanic *kiukinam (source also of Middle Dutch kiekijen, Dutch kieken, Old Norse kjuklingr, Swedish kyckling, German Küken "chicken"), from root *keuk- (echoic of the bird's sound and possibly also the root of cock (n.1)) + diminutive suffixes. By regular sound changes it should have become Modern English *chichen; the reason it didn't is unknown.
Generic words for "chicken" in Indo-European tend to be extended uses of "hen" words, as hens are more numerous than cocks among domestic fowl, but occasionally they are from words for the young, as in English and in Latin (pullus). Meaning "one who is cowardly or timorous" is from 1610s; adjectival sense of "cowardly" is at least as old as 14c. (compare hen-herte "a chicken-hearted person," mid-15c.). As the name of a game of danger to test courage, it is first recorded 1953.
Chicken-feed "paltry sum of money" is by 1897, American English slang; literal use (it is made from the from lowest quality of grain) is by 1834. Chicken lobster "small lobster," is by 1947, American English, apparently from chicken in its sense of "young." To count (one's) chickens before they hatch "anticipate too confidently the obtaining or doing of something" is from 1570s. Chicken-fried steak (1937) is a U.S. Southern recipe that batters, breads, and fries a thin strip of steak in the way fried chicken typically is made.
chicken (v.)
"to back down or fail through cowardice," 1943, U.S. slang, from chicken (n.), almost always with out (adv.). Related: Chickened; chickening.
