Alarm

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.

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.