in Military Art, denotes either the apprehension of being suddenly attacked, or the notice thereof signified by firing a cannon, firelock, or the like. False alarms are frequently made use of to harass the enemy, by keeping them constantly under arms. Sometimes also this method is taken to try the vigilance of the picket-guard, and what might be expected from them in case of real danger.

in Fencing, is the same with what is otherwise called an appeal or challenge.