scuba

noun

1. a portable breathing device for free-swimming divers, consisting of a mouthpiece joined by hoses to one or two tanks of compressed air that are strapped on the back.
2. scuba diving.

verb (used without object), scu·baed, scu·ba·ing.

3. scuba-dive.

noun

1. 1. an apparatus used in skindiving, consisting of a cylinder or cylinders containing compressed air attached to a breathing apparatus
   2. (as modifier)scuba diving

1952, acronym for self-contained underwater breathing apparatus.