be on the lookout for
US /bi ɑn ðə ˈlʊkˌaʊt fɔr/
UK /bi ɑn ðə ˈlʊkˌaʊt fɔr/

1.
waspada terhadap, mencari
to be actively watching or searching for something or someone
:
•
We need to be on the lookout for any suspicious activity.
Kita harus waspada terhadap aktivitas mencurigakan apa pun.
•
The police are on the lookout for the escaped prisoner.
Polisi sedang mencari tahanan yang kabur.