aquanaut

[ ak-wuh-nawt, -not, ah-kwuh- ]
/ ˈæk wəˌnɔt, -ˌnɒt, ˈɑ kwə- /

noun

an undersea explorer, especially one who skin-dives from or lives for an extended period of time in a submerged dwelling.
a skin-diver.

Origin of aquanaut

1880–85; aqua- + -naut, on the model of aeronaut, astronaut, etc.

British Dictionary definitions for aquanaut

aquanaut
/ (ˈækwənɔːt) /

noun

a person who lives and works underwater
a person who swims or dives underwater

Word Origin for aquanaut

C20: from aqua + -naut, as in astronaut