The Oxford Thesaurus An A-Z Dictionary of Synonyms - act n.

1) deed, action, undertaking, operation, step, move; feat, exploit; accomplishment, achievement: The first act of the new commission was to ban smoking in public places. 2) performance, show, bit, skit, stand, routine, turn, sketch, Colloq thing, Slang US shtick: Stand-up comedians do their acts in nightclubs. 3) performance, pretence, posture, stance, feigning, front, fake, dissimulation, show, deception, hoax, affectation: She didn't mean what she said - it was just an act. 4) bill, law, decree, edict, statute, order, ordinance, command, mandate, resolution, measure, enactment: Are the opening hours of public houses in England regulated by act of Parliament? --v. 5) behave (oneself) , carry on, deport oneself, comport oneself, conduct oneself: I don't know how she'll act when we're in public. 6) perform, play, do: She is acting in the West End. 7) portray, represent, impersonate, act out, personify, take or play the part or role of, personate: Reginald acts the fool whenever he has had too much to drink. 8) feign, pretend, counterfeit, fake, dissemble, make believe, sham, simulate, dissimulate, posture: You may think him sincere, but I know he is just acting. 9) take effect, work, operate, function, perform: This drug will act only if taken with meals.