A summons to arms, as on the approach of an enemy.

Any sound or information intended to give notice of approaching danger; a warning sound to arouse attention; a warning of danger.

A sudden attack; disturbance.

Sudden surprise with fear or terror excited by apprehension of danger; in the military use, commonly, sudden apprehension of being attacked by surprise.

A mechanical device for awaking people, or rousing their attention.

"The clock radio is a friendlier version of the cold alarm by the bedside."

An instance of an alarm ringing, beeping or clanging, to give a noise signal at a certain time.

"You should set the alarm on your watch to go off at seven o'clock."

To call to arms for defense

To give (someone) notice of approaching danger

To rouse to vigilance and action; to put on the alert.

To surprise with apprehension of danger; to fill with anxiety in regard to threatening evil; to excite with sudden fear.

To keep in excitement; to disturb.