The Collaborative International Dictionary of English v.0.48:
Plunge \Plunge\, v. t. [imp. & p. p. Plunged; p. pr. & vb. n.
Plunging.] [OE. ploungen, OF. plongier, F. plonger, fr.
(assumed) LL. plumbicare, fr. L. plumbum lead. See Plumb.]
1. To thrust into water, or into any substance that is
penetrable; to immerse; to cause to penetrate or enter
quickly and forcibly; to thrust; as, to plunge the body
into water; to plunge a dagger into the breast. Also used
figuratively; as, to plunge a nation into war. "To plunge
the boy in pleasing sleep." --Dryden.
Bound and plunged him into a cell. --Tennyson.
We shall be plunged into perpetual errors. --I.
2. To baptize by immersion.
3. To entangle; to embarrass; to overcome. [Obs.]
Plunged and graveled with three lines of Seneca.