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."