Standard Synonyms
Vigilant
Watchful
Wakeful
Responsive
Aware
Attentive
Slang Synonyms
Suspicious
Watchful
On guard.
Academic Synonyms
Attentive
Watchful
Careful
Heedful
Vigilant
Old English Synonyms
Regional Synonyms
Vigilant
Watchful
Wide awake
On the ball
Attentive
Sharp
Reheated
Mindful
Outward
Industry-specific Synonyms
Antonyms
Lethargic
Sluggish
Inactive
Drowsy.
Meaning
The definition of alert is “a state of readiness to respond to an opportunity or threat.”
Definition
to be vigilant; to pay attention to possible danger
Example Sentences
I was alert for any sign of danger.
The police are on alert for a suspect in a black hoodie.
I need coffee to keep me alert.
I set an alarm to alert me when it’s time to leave.
Please be alert for potholes in the road.