act verb

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