on the alert

Idioms  

1. Watchful, fully prepared, as in The inspectors are always on the alert for a manufacturing error. [Late 1700s]

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Example Sentences

It’s a play on the alert that heralded a new participant in online chat rooms of the 1990s and aughts, a time when many of this phrase’s current users weren’t born.

From The Wall Street Journal

Motorists have been warned to be on the alert for scammers posing as car finance lenders offering fake compensation.

From BBC

People are being warned to be on the alert for flying debris and falling trees, along with large waves hitting sea fronts, homes and roads.

From BBC

But the WHO said the certification was only "the beginning of a new phase", urging Egypt to be on the alert to preserve its malaria-free status.

From BBC

The president said officials would be on the alert for signs of prices being unfairly hiked in the event of potential shortages.

From BBC