Dictionary 1. (v. t. & i.) One who does; one performs or executes; one who is wont and ready to act; an actor; an agent.2. (v. t. & i.) An agent or attorney; a factor. Thesaurus activist ball of fire beaver big-time operator bustler busy bee eager beaver enthusiast go-getter human dynamo hustler live wire man of action man of deeds militant new broom operator political activist powerhouse take-charge guy wheeler-dealer winner |