verb, plunged, plung⋅ing, noun | 1. | to cast or thrust forcibly or suddenly into something, as a liquid, a penetrable substance, a place, etc.; immerse; submerge: to plunge a dagger into one's heart. |
| 2. | to bring suddenly or forcibly into some condition, situation, etc.: to plunge a country into war; to pull a switch and plunge a house into darkness. |
| 3. | Horticulture. to place (a potted plant) up to its rim in soil or in certain other materials, as sand or moss. |
| 4. | Surveying. to transit (the telescope of a transit or theodolite). |
| 5. | to cast oneself, or fall as if cast, into water, a hole, etc. |
| 6. | to rush or dash with headlong haste: to plunge through a crowd. |
| 7. | to bet or speculate recklessly: to plunge on the stock market. |
| 8. | to throw oneself impetuously or abruptly into some condition, situation, matter, etc.: to plunge into debt. |
| 9. | to descend abruptly or precipitously, as a cliff, road, etc. |
| 10. | to pitch violently forward, as a horse, ship, etc. |
| 11. | act of plunging. |
| 12. | a leap or dive, as into water. |
| 13. | a headlong or impetuous rush or dash: a plunge into danger. |
| 14. | a sudden, violent pitching movement. |
| 15. | a place for plunging or diving, as a swimming pool. |
| 16. | Geology. pitch (def. 48). |
| 17. | take the plunge, to enter with sudden decision upon an unfamiliar course of action, as after hesitation or deliberation: She took the plunge and invested her entire savings in the plan. |