Definition of "Act" :

noun: something that people do or cause to happen

noun: a legal document codifying the result of deliberations of a committee or society or legislative body

noun: a short performance that is part of a longer program

"He did his act three times every evening."

noun: a subdivision of a play or opera or ballet

noun: a manifestation of insincerity

"He put on quite an act for her benefit."

verb: behave in a certain manner; show a certain behavior; conduct or comport oneself

"You should act like an adult."

verb: pretend to have certain qualities or state of mind

"He acted the idiot."

verb: discharge one's duties

"She acts as the chair."

verb: play a role or part

"She wants to act Lady Macbeth, but she is too young for the role."

verb: perform on a stage or theater

"She acts in this play."

verb: behave unnaturally or affectedly

"She's just acting."

verb: perform an action, or work out or perform (an action)

"Think before you act."

verb: be engaged in an activity, often for no particular purpose other than pleasure

verb: have an effect or outcome; often the one desired or expected

"How does your idea work in practice?."

verb: be suitable for theatrical performance

"This scene acts well."