mid-14c., "given to worldly activity" (opposed to contemplative or monastic), from Old French actif (12c.) or directly from Latin activus, from actus (see act (n.)). As "capable of acting" (opposed to passive), from late 14c. Meaning "energetic, lively" is from 1590s; that of "working, effective, in operation" is from 1640s. Active voice is recorded from 1765 (grammatical use of active dates from mid-15c.).
1. In April 1944 he was killed on active service.
2. His daughter was very active and noisy in the mornings.
3. An active and expansive market economy is a necessary condition for progress.
4. The active ingredient in some of the mouthwashes was simply detergent.
5. I am an active member of the Conservative Party.