alarm

/əˈlɑːm/

#4,122 of the most-used English words

noun

1. A summons to arms, as on the approach of an enemy.
2. Any sound or information intended to give notice of approaching danger; a warning sound to arouse attention; a warning of danger.
3. A sudden attack; disturbance.
4. Sudden surprise with fear or terror excited by apprehension of danger; in the military use, commonly, sudden apprehension of being attacked by surprise.

verb

1. To call to arms for defense
2. To give (someone) notice of approaching danger
3. To rouse to vigilance and action; to put on the alert.
4. To surprise with apprehension of danger; to fill with anxiety in regard to threatening evil; to excite with sudden fear.