"one who assails," 1530s, from French assailant, noun use of present participle of assailir (see assail). Earlier in same sense was assailer (c. 1400).

"act of assassinating," c. 1600, noun of action from assassinate (v.). Earlier was assassinment (1570s).

late 14c., "an order, request, directive," from Old French assignement "(legal) assignment (of dower, etc.)," from Late Latin assignamentum, noun of action from past-participle stem of Latin assignare/adsignare "to allot, assign, award" (see assign). The meaning "appointment to office" is mid-15c.; that of "a task assigned (to someone), commission" is by 1848.

"resulting from association," 1804, from associate (v.) + -ive.

1610s, "action of arranging into kinds or classes," from assort + -ment. The sense of "group of things of the same sort" is attested from 1759; that of "group of arranged things whether of the same sort or not" from 1791.

1570s, "an act of assistance," from assist (v.). In the sporting sense attested 1877 in baseball, 1925 in ice hockey.

"legal action for recovery of damages through breach of contract," legal Latin, literally "he has taken upon himself," perfect indicative of assumere "to take up, take to oneself" (see assume). The word embodies the allegation that the defendant promised or undertook to perform the specified act.

"characterized by assimilation; capable of assimilating or of causing assimilation," 1520s; see assimilate + -ive. Alternative assimilatory is from 1775.

"ineffectual," 1932; "Dictionary of American Slang" suggests it is perhaps a humorous mispronunciation of haphazard. Compare half-hearted.

"attack violently," c. 1200, from Old French assalir "attack, assault, assail" (12c., Modern French assaillir), from Vulgar Latin *adsalire "to leap at," from Latin ad "to, toward" (see ad-) + salire "to leap" (see salient (adj.)). The figurative use, of mental states, emotions, etc., is from mid-14c.; the meaning "attack with arguments, abuse, criticism, etc." is from c. 1400. Related: Assailed; assailing; assailable.