alarm

alarm is a Noun

Definition:

[1] A summons to arms, as on the approach of an enemy. Arming to answer in a night alarm. Shak.

[2] Any sound or information intended to give notice of approaching danger; a warming sound to arouse attention; a warning of danger. Sound an alarm in my holy mountain. Joel ii. 1.

[3] A sudden attack; disturbance; broil. [R.] "These home alarms." Shak. Thy palace fill with insults and alarms. Pope.

[4] Sudden surprise with fear or terror excited by apprehension of danger; in the military use, commonly, sudden apprehension of being attacked by surprise. Alarm and resentment spread throughout the camp. Macaulay.

[5] A mechanical contrivance for awaking persons from sleep, or rousing their attention; an alarum. Alarm bell, a bell that gives notice on danger. -- Alarm clock or watch, a clock or watch which can be so set as to ring or strike loudly at a prearranged hour, to wake from sleep, or excite attention. -- Alarm gauge, a contrivance attached to a steam boiler for showing when the pressure of steam is too high, or the water in the boiler too low. -- Alarm post, a place to which troops are to repair in case of an alarm.