2act verb
acts; act·ed; act·ing 1 [no obj] : to do something : to take action
▪ Think before you act. ▪ He knew he had to act quickly/fast. ▪ The government was slow to act. ▪ The firefighters acted with great courage. = They acted courageously. ▪ She acted on behalf of her father, who was not at the meeting. ▪ I believe that the killer acted alone. ▪ She had acted in self-defense when she killed her attacker. ▪ We were acting in the best interests of our children. ▪ If he refuses to cooperate, he'll be acting against his own (best) interests. [=he'll be acting in a way that is harmful to himself] ▪ We must act soon to end this crisis. 2 [no obj] : to behave in a particular way
▪ She learned at an early age how to act properly in social situations. ▪ People are always telling me how I should act and what I should say. ▪ I noticed that the dog was acting funny/differently/strangely this morning. ▪ acting more naturally/aggressively/responsibly ▪ She's been acting kind of crazy lately. ▪ Please learn the new rules and act accordingly. [=follow the new rules] ◊To act the part is to behave the way that people in a particular role usually behave.
▪ Now that he's rich he certainly acts the part. [=behaves like a rich person] ◊To act your age is to behave the way that people your age should behave and not to behave like a younger person.
▪ John, act your age. You're not a kid anymore. ◊To act like a particular kind of person or thing is to behave the way that person or thing behaves.
▪ You two are acting like children. ▪ It's time you start acting like a man. ▪ I'm sorry about yesterday. I acted like a fool/jerk. — see also 2act 3c (below) 3 a [no obj] : to behave in a way that is not sincere or honest
▪ Stop acting. We know you're guilty.
b [linking verb] : to pretend to be something
▪ Stop acting innocent. ▪ She was terribly nervous, but she acted confident. ▪ I know you're bored, but can you at least try to act interested. ▪ He did his best to act excited. ▪ There she goes, offering advice and acting the expert. [=pretending to be an expert] ▪ If anybody asks you where I am, act dumb. [=pretend that you do not know]
c [no obj] : to pretend that something is true — usually used in the phrases act as if, act as though, and (chiefly US) act like ▪ She acted as if nothing had happened. ▪ We acted as though we knew what was going on. ▪ I tried to act like it didn't bother me, but it did. ▪ Even if you don't like your gift, you should act like you do. ▪ I didn't act like it, but I really was happy. — see also act like at 2act 2 (above) 4 : to perform the words and actions of a character in a play, movie, etc. : to perform as an actor [no obj] ▪ It had always been his dream to act. ▪ She can sing, dance, and act. ▪ As a child, she began acting in television commercials. ▪ Both actors have agreed to act in the movie. [+ obj] ▪ He'll be acting the part of Romeo in tonight's play. ▪ The role of Romeo was wonderfully acted by Mr. Jacob Smith. ▪ a beautifully acted movie [=a movie in which the acting is excellent] 5 [no obj] : to do the work of a particular kind of person or thing : to perform a certain function or role — + as ▪ A young man acted [=served] as our guide through the city. ▪ She'll be acting as her own attorney during the court trial. ▪ She agreed to act as his secretary. ▪ The trees act as a source of shade and protection from the wind. 6 [no obj] : to make something happen : to have a particular effect
▪ The chemical acts [=works] by destroying the cells in the brain. — often + on ▪ These medicines act on [=affect] the heart. — see also act on/upon (below)
▪ Think before you act. ▪ He knew he had to act quickly/fast. ▪ The government was slow to act. ▪ The firefighters acted with great courage. = They acted courageously. ▪ She acted on behalf of her father, who was not at the meeting. ▪ I believe that the killer acted alone. ▪ She had acted in self-defense when she killed her attacker. ▪ We were acting in the best interests of our children. ▪ If he refuses to cooperate, he'll be acting against his own (best) interests. [=he'll be acting in a way that is harmful to himself] ▪ We must act soon to end this crisis.
▪ She learned at an early age how to act properly in social situations. ▪ People are always telling me how I should act and what I should say. ▪ I noticed that the dog was acting funny/differently/strangely this morning. ▪ acting more naturally/aggressively/responsibly ▪ She's been acting kind of crazy lately. ▪ Please learn the new rules and act accordingly. [=follow the new rules] ◊To act the part is to behave the way that people in a particular role usually behave.
▪ Now that he's rich he certainly acts the part. [=behaves like a rich person] ◊To act your age is to behave the way that people your age should behave and not to behave like a younger person.
▪ John, act your age. You're not a kid anymore. ◊To act like a particular kind of person or thing is to behave the way that person or thing behaves.
▪ You two are acting like children. ▪ It's time you start acting like a man. ▪ I'm sorry about yesterday. I acted like a fool/jerk. — see also 2act 3c (below)
▪ Stop acting. We know you're guilty.
b [linking verb] : to pretend to be something
▪ Stop acting innocent. ▪ She was terribly nervous, but she acted confident. ▪ I know you're bored, but can you at least try to act interested. ▪ He did his best to act excited. ▪ There she goes, offering advice and acting the expert. [=pretending to be an expert] ▪ If anybody asks you where I am, act dumb. [=pretend that you do not know]
c [no obj] : to pretend that something is true — usually used in the phrases act as if, act as though, and (chiefly US) act like ▪ She acted as if nothing had happened. ▪ We acted as though we knew what was going on. ▪ I tried to act like it didn't bother me, but it did. ▪ Even if you don't like your gift, you should act like you do. ▪ I didn't act like it, but I really was happy. — see also act like at 2act 2 (above)
▪ The chemical acts [=works] by destroying the cells in the brain. — often + on ▪ These medicines act on [=affect] the heart. — see also act on/upon (below)
act on/upon [phrasal verb]
act on/upon (something) : to use (something, such as a feeling or suggestion) as a reason or basis for doing something
▪ They never acted on the information they had. ▪ We were too late to act upon his suggestion. ▪ It's okay to feel angry or jealous, but you mustn't act on those feelings. — see also 2act 6 (above)
▪ They never acted on the information they had. ▪ We were too late to act upon his suggestion. ▪ It's okay to feel angry or jealous, but you mustn't act on those feelings. — see also 2act 6 (above)
act out [phrasal verb] 1 a : to behave badly especially because you are feeling painful emotions (such as fear or anger)
▪ What can parents do when their kids start acting out?
b act out (something) or act (something) out : to show that you are feeling (a painful emotion) by acting in ways that are not good or acceptable
▪ children acting out their emotions in inappropriate ways ▪ He tries not to act out his anger/frustrations. 2 act out (something) or act (something) out a : to perform (a play, a character in a movie, etc.)
▪ plays acted out on stage ▪ She skillfully acted out the role of a young queen.
b : to do and say the things that happen in (a movie, past event, etc.)
▪ At their last party, they acted out [=reenacted] scenes from old movies. ▪ The children were acting out what they saw on television. ▪ adults acting out their childhood dreams/fantasies [=doing the things they wanted to do when they were children]
▪ What can parents do when their kids start acting out?
b act out (something) or act (something) out : to show that you are feeling (a painful emotion) by acting in ways that are not good or acceptable
▪ children acting out their emotions in inappropriate ways ▪ He tries not to act out his anger/frustrations.
▪ plays acted out on stage ▪ She skillfully acted out the role of a young queen.
b : to do and say the things that happen in (a movie, past event, etc.)
▪ At their last party, they acted out [=reenacted] scenes from old movies. ▪ The children were acting out what they saw on television. ▪ adults acting out their childhood dreams/fantasies [=doing the things they wanted to do when they were children]
act the fool — see 1fool
act up [phrasal verb] 1 : to behave badly : to act in a way that is not polite or acceptable
▪ The kids are acting up [=misbehaving] again. ▪ The book gives advice to parents whose children act up. 2 of a machine : to not work properly
▪ The camera started acting up [=malfunctioning] after I dropped it. 3 of a disease : to become worse and to start causing pain or physical problems
▪ His asthma acts up when it's cold outside. ▪ Whenever it rains, my arthritis starts acting up.
▪ The kids are acting up [=misbehaving] again. ▪ The book gives advice to parents whose children act up.
▪ The camera started acting up [=malfunctioning] after I dropped it.
▪ His asthma acts up when it's cold outside. ▪ Whenever it rains, my arthritis starts acting up.
