late 14c., misusen, "use or treat improperly;" from mis- (1) "badly, wrongly" + use (v.) and in part from Old French mesuser (Modern French méuser), from mis- (2). Meaning "abuse, treat badly, subject to ill-treatment" is attested from 1530s. Related: Misused; misusing; misusage.
late 14c., "improper use, misapplication," from mis- (1) "bad, wrong" + use (n.) and in part from Old French mesus "abuse, excess, misdeed." As "abuse, ill-treatment" it is attested from 1590s.
prefix of Germanic origin affixed to nouns and verbs and meaning "bad, wrong," from Old English mis-, from Proto-Germanic *missa- "divergent, astray" (source also of Old Frisian and Old Saxon mis-, Middle Dutch misse-, Old High German missa-, German miß-, Old Norse mis-, Gothic missa-), perhaps literally "in a changed manner," and with a root sense of "difference, change" (compare Gothic misso "mutually"), and thus possibly from PIE *mit-to-, from root *mei- (1) "to change."
Productive as word-forming element in Old English (as in mislæran "to give bad advice, teach amiss"). In 14c.-16c. in a few verbs its sense began to be felt as "unfavorably," and it came to be used as an intensive prefix with words already expressing negative feeling (as in misdoubt). Practically a separate word in Old and early Middle English (and often written as such). Old English also had an adjective (mislic "diverse, unlike, various") and an adverb (mislice "in various directions, wrongly, astray") derived from it, corresponding to German misslich (adj.). It has become confused with mis- (2).
c. 1200, "employ for a purpose," from Old French user "employ, make use of, practice, frequent," from Vulgar Latin *usare "use," frequentative form of past participle stem of Latin uti "make use of, profit by, take advantage of, enjoy, apply, consume," in Old Latin oeti "use, employ, exercise, perform," of uncertain origin. Related: Used; using. Replaced Old English brucan (see brook (v.)). From late 14c. as "take advantage of."