The Oxford Thesaurus An A-Z Dictionary of Synonyms - activeadj.

1) strenuous, vigorous, full, dynamic, physical; energetic, lively, busy, brisk, bustling, occupied, on the move, Colloq on the go, running: She is healthier for having led a very active life. He always seems to be active. 2) acting, effective, efficacious, effectual, working, functioning, operative, potent, influential; powerful: The active ingredient in her medicine is an antihistamine. 3) energetic, lively, hyperactive, animated, spry, nimble, quick, agile, sprightly: There is no keeping up with an active child.