(intransitive) To dive, leap or rush (into water or some liquid); to submerge oneself.
(figuratively, intransitive) To fall or rush headlong into some thing, action, state or condition.
(intransitive) To pitch or throw oneself headlong or violently forward, as a horse does.
(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.
(intransitive, obsolete) To entangle or embarrass (mostly used in past participle).