mid-14c., determinacioun, "decision, sentence in a suit at law, definite or authoritative judicial settlement," from Old French déterminacion "determination, settlement, definition" (14c.) and directly from Medieval Latin determinationem (nominative determinatio) "conclusion, boundary," noun of action from past-participle stem of Latin determinare "to enclose, bound, set limits to" (see determine).
Meaning "action of definitely ascertaining" is from 1670s; that of "result ascertained, a conclusion" is from 1560s. As "fixed direction toward a goal or terminal point," from 1650s, originally in physics or anatomy; metaphoric sense "fixation of will toward a goal, state of mental resolution with regard to something" is from 1680s; general sense of "quality of being resolute, fixedness of purpose as a character trait" is by 1822.