Plunge

1. The act of thrusting into or submerging; a dive, leap, rush, or pitch into, or as into, water; as, to take the water with a plunge.
2. Hence, a desperate hazard or act; a state of being submerged or overwhelmed with difficulties.
3. The act of pitching or throwing one's self headlong or violently forward, like an unruly horse.
4. Heavy and reckless betting in horse racing; hazardous speculation.
Plunge bath ,
an immersion by plunging; also, a large bath in which the bather can wholly immerse himself.
Plunge battery, or plunging battery (Elec.),
a voltaic battery so arranged that the plates can be plunged into, or withdrawn from, the exciting liquid at pleasure.