- 1 alert somebody (to do something) alert somebody (that)… to warn someone about a dangerous or urgent situation Neighbors quickly alerted the police. Alerted by a noise downstairs, he sat up and turned on the light.
- 2alert somebody to something to make someone aware of something They had been alerted to the possibility of further price rises.
NAmE//əˈlərt//[often passive]Verb Forms present simple I / you / we / they alert
he / she / it alerts
past simple alerted
-ing form alerting