alarum n. 警报机
alarum[ noun ]
an automatic signal (usually a sound) warning of danger
<noun.communication>
Alarum \A*lar"um\ (?; 277), n. [OE. alarom, the same word as
alarm, n.]
See {Alarm}. [Now Poetic]
Note: The variant form alarum is now commonly restricted to
an alarm signal or the mechanism to sound an alarm (as
in an alarm clock.)