To descend or plunge into or under water or other liquid. (Usually, unless otherwise stated, to plunge head-foremost.)

intransitive. (See quot. 1623.)

intransitive. To swim underwater without a deep-sea diving suit. See skin-diving, n.

an underwater dive made by a person wearing goggles; hence as v. intransitive; also goggle-diver, goggle-diving.

(intransitive) to use this equipment.

intransitive. To swim, as a fish; hence used of underwater swimmers. Also transitive, to fin it, to fin a (or one's) passage, way.

(intransitive) to swim under water using such apparatus.