Synonyms and related words :
activist, addict, ball of fire, beaver, big-time operator, bug, bustler, busy bee, collector, demon, doer, energumen, enthusiast, faddist, fanatic, fiend, freak, go-getter, great one for, hobbyist, hound, human dynamo, hustler, infatuate, live wire, man of action, man of deeds, militant, new broom, nut, operator, political activist, powerhouse, pursuer, rhapsodist, sucker for, take-charge guy, visionary, wheeler-dealer, winner, zealot