The story
Aqualung was the original name for the first open-circuit SCUBA diving equipment by Emile Gagnan and Jacques Cousteau in 1943. From aqua- + lung.
Etymology from Wiktionary, CC BY-SA 4.0.
aqualung
Today it means: A piece of equipment consisting of an oxygen tank and breathing apparatus used by divers to allow them to breathe underwater. Full definition →