mid-14c., "given to worldly activity" (opposed to contemplative or monastic), from Old French actif (12c.) and directly from Latin activus, from actus "a doing" (from PIE root *ag- "to drive, draw out or forth, move").
As "capable of acting" (opposed to passive), from late 14c. Meaning "energetic, lively" is from 1590s; that of "working, effective, in operation" (opposed to inactive) is from 1640s. Active voice is recorded from 1765; grammatical use of active, signifying performance and not endurance of an action, dates from mid-15c. (opposed to passive or reflexive).