'Plunging fire' definitions:

Definition of 'Plunging fire'

From: GCIDE

Plunge \Plunge\, v. i.
1. To thrust or cast one's self into water or other fluid; to submerge one's self; to dive, or to rush in; as, he plunged into the river. Also used figuratively; as, to plunge into debt. [1913 Webster]
Forced to plunge naked in the raging sea. --Dryden. [1913 Webster]
To plunge into guilt of a murther. --Tillotson. [1913 Webster]
2. To pitch or throw one's self headlong or violently forward, as a horse does. [1913 Webster]
Some wild colt, which . . . flings and plunges. --Bp. Hall. [1913 Webster]
3. To bet heavily and with seeming recklessness on a race, or other contest; in an extended sense, to risk large sums in hazardous speculations. [Cant] [1913 Webster]
Plunging fire (Gun.), firing directed upon an enemy from an elevated position. [1913 Webster]