A sudden attack; disturbance.
An instance of an alarm ringing, beeping or clanging, to give a noise signal at a certain time.
A mechanical device for awaking people, or rousing their attention.
Any sound or information intended to give notice of approaching danger; a warning sound to arouse attention; a warning of danger.
A summons to arms, as on the approach of an enemy.
Sudden surprise with fear or terror excited by apprehension of danger; in the military use, commonly, sudden apprehension of being attacked by surprise.
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.
To call to arms for defense
To keep in excitement; to disturb.
Agitation; the state of being perturbed
Variation in an orbit due to the influence of external bodies
A small change in a physical system, or more broadly any definable system (such as a biological or economic system)