1 thing that sb does
ADJ. charitable, kind | heroic a heroic act of bravery | aggressive, barbaric, hostile, provocative, terrorist, violent | appalling, despicable, outrageous, terrible | criminal, illegal, unlawful, wrongful | careless, foolish, impulsive | conscious, deliberate, positive, voluntary, wilful | private a private act of revenge | public | creative, dramatic, physical, political, symbolic | homosexual, sex/sexual | balancing, disappearing, juggling, vanishing The UN must perform a difficult balancing act between the two sides in the conflict.
VERB + ACT commit (law), perform charged with committing an act of gross indecency
PREP. in the ~ of (= doing something) | ~ of For Jane, the act of writing was always difficult.
PHRASES an act of faith, love, violence, will, worship, etc., catch sb in the act (of doing sth) He was caught in the act of stealing. | the simple/very act of doing sth The very act of writing out your plan clarifies what you need to do.
2 (also Act) law made by a government
VERB + ACT bring in, introduce, pass The Act was passed by a majority of 175 votes to 143. | amend | repeal The old Act has now been repealed. | breach, contravene The company had breached the 1994 Companies Act.
ACT + VERB become law, come into force The new Children's Act will come into force next year. | contain sth, say sth, state sth The Act contains regulations for banks and building societies.
PREP. under an/the ~ He was charged under the Firearms Act of 1977.
3 entertainment; entertainers
ADJ. class (informal) (used for sb who does sth well) Their new striker looks a class act. | double comedy double act French and Saunders | live their reputation as one of rock's most impressive live acts | main, support The main act will come on at about ten o'clock. | cabaret, circus, comedy, song-and-dance, stage, variety
VERB + ACT do, perform He does a little song-and-dance act. | rehearse, work on
4 division of a play
ADJ. opening | final, last | first, second, etc.
PREP. in (the) ~ The king is killed in the opening act.
5 insincere behaviour
VERB + ACT put on Don't take any notice?she's just putting on an act!
1 do sth/behave
ADV. at once, immediately, promptly, quickly, swiftly The government must act promptly to change this law. | correctly, legally, properly | illegally, improperly, unconstitutionally, unlawfully, wrongly | reasonably, responsibly, sensibly, wisely | dishonestly, dishonourably, unreasonably | oddly, strangely, suspiciously Jenny has been acting rather strangely recently. | bravely | decisively | effectively | in good faith His defence was that he had acted in good faith. | in self defence The jury accepted that he had acted in self defence. | accordingly George knew about the letter and acted accordingly.
PREP. against The government needs to act against the sale of these dangerous toys. | for/on behalf of sb His solicitors are continuing to act for him. | like Stop acting like a spoilt child. hormones in the brain that act like natural painkillers | on Alcohol acts quickly on the brain. | out of I suspected that he was acting out of malice.
PHRASES act in sb's best interests We are all acting in the best interests of the children.
2 perform in play/film
ADV. brilliantly, well | badly