warn

warn

W2S3 [wo:n US wo:rn] v [I and T]

[: Old English; Origin: warnian]

1.) to tell someone that something bad or dangerous may happen, so that they can avoid it or prevent it

▪ 'Be careful, the rocks are slippery,' Alex warned.

warn sb about sth

▪ Travellers to Africa are being warned about the danger of HIV infection.

warn (sb) of sth

▪ Salmon farmers are warning of the severe crisis facing the industry.

warn sb (not) to do sth

▪ I warned you not to walk home alone.

▪ Motorists are being warned to avoid the centre of London this weekend.

warn sb (that)

▪ We warned them that there was a bull in the field.

2.) to tell someone about something before it happens so that they are not worried or surprised by it

warn sb (that)

▪ Warn her you're going to be back late.

warn () against [warn (sb) against sth] phr v

to advise someone not to do something because it may have dangerous or unpleasant results

▪ Her financial adviser warned her against such a risky investment.

warn (sb) against doing sth

▪ The police have warned tourists against leaving the main tourist centres.

warn away [warn sb<=>away] phr v

to tell someone that they should not go near something, especially because it may be dangerous

▪ The snake's markings are intended to warn away predators.

warn sb off [warn sb<=> off] phr v

1.) to tell people that they should not go near something, especially because it might be dangerous

▪ Some animals mark their territory to warn off rivals.

2.) especially BrE to tell someone that they should not do or use something because it might be dangerous

warn sb off doing sth

▪ Doctors should have warned people off using the drug much earlier than they did.