Decrease and Plunge

decrease

A change downward.
- usage: "there was a decrease in his temperature as the fever subsided"; "there was a sharp drop-off in sales"
- synonyms: lessening, drop-off
A process of becoming smaller or shorter.
- synonyms: decrement
The amount by which something decreases.
- synonyms: decrement
The act of decreasing or reducing something.
- synonyms: diminution, reduction, step-down

Decrease in size, extent, or range.
- usage: "The amount of homework decreased towards the end of the semester"; "The cabin pressure fell dramatically"; "her weight fell to under a hundred pounds"; "his voice fell to a whisper"
- synonyms: diminish, lessen, fall
Make smaller.
- usage: "He decreased his staff"
- synonyms: lessen, minify

(v.t.) To cause to grow less; to diminish gradually; as, extravagance decreases one's means.
(v.) A becoming less; gradual diminution; decay; as, a decrease of revenue or of strength.
(n.) To grow less, -- opposed to increase; to be diminished gradually, in size, degree, number, duration, etc. or in strength, quality or excellence; as, they days decrease in length from June to December.
(v.) The wane of the moon.

Webster's Revised Unabridged Dictionary

plunge

Thrust or throw into.
- usage: "Immerse yourself in hot water"
- synonyms: immerse
Drop steeply.
- usage: "the stock market plunged"
- synonyms: dive, plunk
Dash violently or with great speed or impetuosity.
- usage: "She plunged at it eagerly"
Begin with vigor.
- usage: "He launched into a long diatribe"; "She plunged into a dangerous adventure"
- synonyms: launch
Cause to be immersed.
- usage: "The professor plunged his students into the study of the Italian text"
- synonyms: immerse
Fall abruptly.
- usage: "It plunged to the bottom of the well"
- synonyms: dump
Immerse briefly into a liquid so as to wet, coat, or saturate.
- usage: "dip the garment into the cleaning solution"; "dip the brush into the paint"
- synonyms: dunk, dip, souse, douse
Devote (oneself) fully to.
- usage: "He immersed himself into his studies"
- synonyms: steep, immerse, engulf, engross, absorb, soak up

(n.) 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.
(n.) Hence, a desperate hazard or act; a state of being submerged or overwhelmed with difficulties.
(v.t.) To baptize by immersion.
(v.t.) To entangle; to embarrass; to overcome.
(v.i.) To pitch or throw one's self headlong or violently forward, as a horse does.
(n.) Heavy and reckless betting in horse racing; hazardous speculation.
(n.) The act of pitching or throwing one's self headlong or violently forward, like an unruly horse.
(v.i.) To bet heavily and with seeming recklessness on a race or other contest; in an extended sense, to risk large sums in hazardous speculations.
(v.t.) 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.
(v.i.) 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.

Webster's Revised Unabridged Dictionary