(noun) a steep and rapid fall
(verb) begin with vigor; "He launched into a long diatribe"; "She plunged into a dangerous adventure"
(verb) engross (oneself) fully; "He immersed himself into his studies"
(verb) cause to be immersed; "The professor plunged his students into the study of the Italian text"
(verb) immerse briefly into a liquid so as to wet, coat, or saturate; "dip the garment into the cleaning solution"; "dip the brush into the paint"
(verb) thrust or throw into; "Immerse yourself in hot water"
(verb) dash violently or with great speed or impetuosity; "She plunged at it eagerly"
(verb) drop steeply; "the stock market plunged"
(verb) fall abruptly; "It plunged to the bottom of the well"