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.

(transitive) To call to arms for defense / (transitive) To give (someone) notice of approaching danger / (transitive) To rouse to vigilance and action; to put on the alert.

Easily alarmed; excitable. / (rare) Of a building, etc.: capable of being fitted with an alarm system.

plural of alarmism

One who alarms; one who sounds the alarm. / (US, in combination) A multialarm fire of a specified number of alarms.

plural of alarmer

The raising of needless alarms.

Having an alarm fitted. / Worried; anxious; panicky. / 8: Thomas, the groom, in the act of drinking, put down the jug alarmed before his master. Thomas’s master felt the honour keenly.

simple past tense and past participle of alarm

causing apprehension, fear or alarm; frightening