v. 1 descend, drop, plummet, dive, pitch, nosedive, fall (headlong) They lost their footing, and both Holmes and Moriarty plunged into the abyss 2 submerge, sink, immerse; engulf, overwhelm I plunged my hand in the icy water to retrieve the keys She plunged herself into her work to try to forget him.
n. 3 dive, nosedive, fall, pitch, plummet, drop, descent; submersion, immersion After the scandal his career took a plunge from which it never recovered Every winter they take a plunge into the icy waters of the Serpentine. 4 gamble, wager, bet, risk: Are you taking the plunge with an investment in South America?