Origin and history of -ard

"illegitimate child," early 13c., from Old French bastard "acknowledged child of a nobleman by a woman other than his wife" (11c., Modern French bâtard), probably from fils de bast "packsaddle son," meaning a child conceived on an improvised bed (saddles often doubled as beds while traveling), with pejorative ending -art (see -ard).

Compare German bänkling "bastard; child begotten on a bench" (and not in a marriage bed), the source of English bantling (1590s) "brat, small child." Bastard was not always regarded as a stigma; the Conqueror is referred to in state documents as "William the Bastard."

According to OED online: "The most plausible suggestion is that the ulterior etymon is either an unattested variant (without rounding of the vowel) of Old Frisian bōst ‘morganatic marriage’, or an unattested Old Saxon cognate of that word, both (with loss of nasal and compensatory lengthening) < the Indo-European base of bind v."

The figurative sense of "thing not pure or genuine" is by late 14c. Its use as a generic vulgar term of abuse for a man is attested from 1830. Among the "bastard" words in Halliwell-Phillipps' "Dictionary of Archaic and Provincial Words" are avetrol, chance-bairn, by-blow, harecoppe, horcop, and gimbo ("a bastard's bastard").

As an adjective from late 14c. It is used of things spurious or not genuine, having the appearance of being genuine, of abnormal or irregular shape or size, and of mongrels or mixed breeds.

c. 1300, "type of hawk not used in falconry," from Old French buisart "harrier, inferior hawk," from buson, buison, apparently from Latin buteonem (nominative buteo) a kind of hawk ("but the process of formation is not evident" - OED), perhaps with -art suffix for one that carries on some action or possesses some quality, with derogatory connotation (see -ard). In the New World the word was extended to the American vulture (by 1830s). De Vaan says buteo is "Probably onomatopoeic, rendering the call of a hawk or buzzard."