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.
Forced to plunge naked in the raging sea. Dryden.
To plunge into guilt of a murther. Tillotson.
2. To pitch or throw one's self headlong or violently forward, as a horse does.
Some wild colt, which... flings and plunges. Bp. Hall.
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.
Plunging fire(Gun.), firing directed upon an enemy from an elevated position.