comparative form of alert: more alert

Very attentive, or vigilant

A community in the Qikiqtaaluk Region, Nunavut, Canada; the northernmost permanently inhabited place in the world.

plural of alertness

plural of alerter

on guard

(programming) Capable of receiving and responding to notifications from other threads of execution.

(US, Canada) A public notification of a child abduction.

A warning that indicates an emergency situation. / A state of readiness to deal with such emergency situation.

plural of amber alert