1) Military tactic 
Harassing fire is a form of psychological warfare in which an enemy force is subjected to random, unpredictable and intermittent small-arms or artillery fire over an extended period of time (usually at night and times of low conflict intensity) in an effort to undermine morale, increase the enemy`s stress levels and deny them the opportunity for ....
Harassing fire is weapons fire designed to lower morale of the troops under fire through denial of sleep, noise, and constant danger. Usually sustained or sporadic over a long period of time.
[n] - fire designed to disturb the rest of enemy troops and to curtail movement and to lower enemy morale
noun fire designed to disturb the rest of enemy troops and to curtail movement and to lower enemy morale