on watch for (someone or something)

on watch for (someone or something)

Actively and attentively looking out for someone or something. You need to be on watch for suspicious people when you're out in the city this late at night. We've had to put extra inspectors on watch for counterfeit products being smuggled through the shipping yard.
See also: on, watch
Farlex Dictionary of Idioms.
See also:
  • on the watch
  • on the watch (for someone or something)
  • be on the watch
  • be on the watch (for someone or something)
  • lend (someone) (one's) ear
  • be wise to (someone or something)
  • be/get wise to somebody/something
  • glom
  • glom (someone or something)
  • glommed