plunge

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To thrust or throw forcefully into a substance or place: "Plunge the lobsters, head first, into a large pot of rapidly boiling salted water” ( Craig Claiborne).
2. v. To cast suddenly, violently, or deeply into a given state or situation: "The street was plunged in cool shadow” ( Richard Wright).
3. v. To fall or throw oneself into a substance or place: We plunged into the icy mountain lake.
4. v. To throw oneself earnestly or wholeheartedly into an activity or situation: plunged into my studies.
5. v. To enter or move headlong through something: The hunting dogs plunged into the forest.
6. v. To descend steeply; fall precipitously: a cliff that plunges to the sea.
7. v. To move forward and downward violently: The rider plunged from the bucking horse.
8. v. To become suddenly lower; decrease dramatically: Stock prices plunged during the banking crisis.
9. v. To speculate or gamble extravagantly.
10. n. The act or an instance of plunging.
11. n. A place or area, such as a swimming pool, for diving or plunging.
12. n. A swim; a dip.
13. idiom. take the plunge Informal To begin an unfamiliar venture, especially after hesitating: After a three-year engagement, they're finally taking the plunge.

Century Dictionary and Cyclopedia

1. To cast or thrust suddenly into water or some other fluid, or into some penetrable substance; immerse; thrust: as, to plunge one's hand into the water; to plunge a dagger into one's breast.
2. Figuratively, to cast or throw into some thing, state, condition, or action: as, plunged in grief; to plunge a nation into war.
3. To entangle or embarrass: used chiefly in the past participle.
4. To dive, leap, or rush (into water or some fluid).
5. To fall or rush headlong into some thing, action, state, or condition: as, to plunge into debt or into a controversy.
6. To throw the body forward and the hind legs up, as an unruly horse.
7. To descend precipitously or vertically, as a cliff.
8. To bet recklessly; gamble for large stakes; speculate.
9. n. A sudden dive, leap, or dip into something: as, a plunge in the sea.
10. n. An immersion in difficulty, embarrassment, or distress; the condition of being surrounded or overwhelmed; a strait; difficulty.
11. n. A sudden and violent pitching forward of the body, and pitching up of the hind legs, as by an unruly horse
12. In horticulture, to sink (a pot or box containing a plant) in the ground to the rim or edge. Pots of greenhouse plants are often plunged in the open in warm weather, both for the good of the plants and for their effect in ornamentation.
13. To turn over (the telescope of a surveyor's transit or theodolite) in a vertical plane, making the object-glass pass underneath. In transiting the telescope it may pass either above or below.
14. In geology, to dip under the surface: used in reference to such structural features as folds where, unless the axis is perfectly horizontal, one end pitches below the horizon or general surface.

Wiktionary

1. n. the act of plunging or submerging
2. n. a dive, leap, rush, or pitch into (into water)
3. n. figuratively the act of pitching or throwing one's self headlong or violently forward, like an unruly horse
4. n. slang heavy and reckless betting in horse racing; hazardous speculation
5. n. obsolete an immersion in difficulty, embarrassment, or distress; the condition of being surrounded or overwhelmed; a strait; difficulty
6. v. transitive to thrust into water, or into any substance that is penetrable; to immerse;
7. v. figuratively, transitive to cast or throw into some thing, state, condition or action
8. v. transitive, obsolete to baptize by immersion
9. v. intransitive to dive, leap or rush (into water or some liquid); to submerge one's self
10. v. figuratively, intransitive to fall or rush headlong into some thing, action, state or condition
11. v. intransitive to pitch or throw one's self headlong or violently forward, as a horse does
12. v. intransitive, slang to bet heavily and with seeming recklessness on a race, or other contest; in an extended sense, to risk large sums in hazardous speculations
13. v. intransitive, obsolete to entangle or embarrass (mostly used in past participle)
14. v. intransitive, obsolete to overwhelm, overpower

GNU Webster's 1913

1. v. To thrust into water, or into any substance that is penetrable; to immerse; to cause to penetrate or enter quickly and forcibly; to thrust. Also used figuratively.
2. v. To baptize by immersion.
3. v. obsolete To entangle; to embarrass; to overcome.
4. v. To thrust or cast one's self into water or other fluid; to submerge one's self; to dive, or to rush in. Also used figuratively.
5. v. To pitch or throw one's self headlong or violently forward, as a horse does.
6. v. Cant To bet heavily and with seeming recklessness on a race, or other contest; in an extended sense, to risk large sums in hazardous speculations.
7. n. The act of thrusting into or submerging; a dive, leap, rush, or pitch into, or as into, water.
8. n. rare Hence, a desperate hazard or act; a state of being submerged or overwhelmed with difficulties.
9. n. The act of pitching or throwing one's self headlong or violently forward, like an unruly horse.
10. n. Cant Heavy and reckless betting in horse racing; hazardous speculation.

WordNet 3.0

1. v. dash violently or with great speed or impetuosity
2. v. thrust or throw into
3. v. begin with vigor
4. v. fall abruptly
5. v. drop steeply
6. v. cause to be immersed
7. v. devote (oneself) fully to
8. n. a steep and rapid fall
9. n. a brief swim in water
10. v. immerse briefly into a liquid so as to wet, coat, or saturate