c. 1300, "completely, altogether, entirely, wholly," adverbial form of Middle English quit, quite (adj.) "free, clear" (see quit (adj.)). Originally "thoroughly;" the weaker sense of "fairly" is attested from mid-19c. For quite a few, etc., see few (adj.). In Middle English the adverb also could be quitely, quitelich, quitli (c. 1300).

early 15c., "rent paid by a tenant of a manor in exchange for being discharged from required service;" also, "nominal rent as acknowledgment of tenure," from quit (adj.) + rent (n.).

"on even terms with one another," in to be quits (with one) "have made a mutual satisfaction of claims or demands," 1660s; earlier "discharged of a liability" (c. 1200), perhaps from Medieval Latin quittus (see quit (adj.)). An adjective used as a quasi-noun in plural form. Quit (adj.) "satisfied" is attested from c. 1400.

in law, "a relinquishing of a legal right or claim, a deed of release," c. 1300, from Anglo-French quiteclame; see quit (v.) + claim (n.). Compare Old French clamer quitte "to give up (a right)." Related: Quitclaimance.

as an insult, "one who shirks or gives up," by 1878, American English, in reference to race horses, agent noun from quit (v.) in the "stop, cease" sense. It is attested by 1871 as "one who gives up (chewing tobacco)."

c. 1400, requiten, "make return for, repay" (for good or ill), from Old French requiter or formed in English from re- "back" + Middle English quite "clear, pay up," an early variant of quit (v.) preserved in this word; in early use requite was often requit. Related: Requited; requiting.