cowardly adj.

"one who lacks courage to meet danger or shrinks from the chance of being hurt," mid-13c., from Anglo-French couard, couart, Old French coart "coward" (no longer the usual word in French, which has now in this sense poltron, from Italian, and lâche), from coe "tail," from Latin coda, popular dialect variant of cauda "tail" (see coda) + -ard, an agent noun suffix denoting one that carries on some action or possesses some quality, with derogatory connotation (see -ard).

The word probably reflects an animal metaphoric sense still found in expressions like turning tail and tail between legs. Coart was the name of the hare in Old French versions of "Reynard the Fox." Italian codardo, Spanish cobarde (Old Spanish couarde) are from French. The spelling in English was influenced by cow (v. and n.).

[S]o strong is the false belief that every bully must be a coward that acts requiring great courage are constantly described as cowardly or dastardly if they are so carried out as not to give the victim a sporting chance; the throwing of a bomb at a king's carriage is much less dastardly than shooting a partridge, because the thrower takes a very real risk .... [Fowler]

As a surname (attested from mid-13c.) it represents Old English cuhyrde "cow-herd." As an adjective, "lacking courage, timorous," from late 13c. Farmer has coward's castle "a pulpit," "Because a clergyman may deliver himself therefrom without fear of contradiction or argument."

suffix forming adjectives from nouns and meaning "having qualities of, of the form or nature of" (manly, lordly), "appropriate to, fitting, suited to" (bodily, earthly, daily); irregularly descended from Old English -lic, from Proto-Germanic *-liko- (Old Frisian -lik, Dutch -lijk, Old High German -lih, German -lich, Old Norse -ligr), related to *likom- "appearance, form" (Old English lich "corpse, body;" see lich, which is a cognate; see also like (adj.), with which it is identical).

common adverbial suffix, forming from adjectives adverbs signifying "in a manner denoted by" the adjective, Middle English, from Old English -lice, from Proto-Germanic *-liko- (cognates: Old Frisian -like, Old Saxon -liko, Dutch -lijk, Old High German -licho, German -lich, Old Norse -liga, Gothic -leiko); see -ly (1). Cognate with lich, and identical with like (adj.).

Weekley notes as "curious" that Germanic uses a word essentially meaning "body" for the adverbial formation, while Romanic uses one meaning "mind" (as in French constamment from Latin constanti mente). The modern English form emerged in late Middle English, probably from influence of Old Norse -liga.