The Collaborative International Dictionary of English v.0.48:
aqualung \aqualung\ n. an apparatus containing compressed air or other oxygen-gas mixture, permitting a person to breathe under water; -- also called a scuba. Syn: scuba [WordNet 1.5 +PJC]WordNet (r) 3.0 (2006):
Aqua-Lung n 1: a device (trade name Aqua-Lung) that lets divers breathe under water; scuba is an acronym for self-contained underwater breathing apparatus [syn: aqualung, Aqua- Lung, scuba]