英和和英

to warn

take warning

to withdraw a warning

relax one's vigilance

an indication or sign suggesting cautiousness

exercise [use] caution

an early warning

to go at regular intervals round an area to see that there is no trouble

a warning-signal

to keep strict guard

the action of taking or making strict precautions against something

a warning to be ready for danger

the act of taking precautions by patrolling

We need to stay alert.

Forewarned is forearmed.

You can't be too vigilant.

a state of emergency about which a warning needs to be issued

We must guard against accidents―take precautions against accidents.

a loud warning signal produced by a burglar alarm

to develop alarming symptoms

to be cautious of one's surroundings

to guard with strict vigilance

an early‐warning radar

the state there being heavy security

a whistle that is used to signal a warning

an early warning device called {sentry alarm}

the condition of there being heavy security

an early‐warning system

a warning sign

There are signs of the epidemic spreading, and the Metropolitan Police are on their guard against it.