aquanaut

American  

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

noun

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

2. a skin-diver.

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aquanaut British  

/ ˈækwənɔːt /

noun

1. a person who lives and works underwater

2. a person who swims or dives underwater

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Etymology

Origin of aquanaut

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

Explanation

An aquanaut is someone who explores the underwater world in some way. They might go diving with specialized equipment, or live for a short time in underwater domes to do research. The word aqua means "water," and the word naut means "sailor," as in nautical. You might be thinking "Hey, aren't sailors already associated with water?" and that's true. Aquanaut was actually coined to be similar to astronaut, which literally means "star-sailor." So an aquanaut is someone who explores or temporarily lives and works underwater, similar to how astronauts explore or temporarily live and work in space.

Example Sentences

As part of her training, she spent 18 days as an aquanaut living in an undersea habitat.

From BBC • Mar. 15, 2026

Only one aquanaut was deeply involved in all four stages of that grand adventure: Mr. Barth, who died on March 26 at his home in Panama City, Fla., at 89.

From New York Times • Apr. 7, 2020

Then again, an astronaut or an aquanaut sees unimaginable new worlds, whereas your brother sees only a monocolor haze of varying intensities.

From The New Yorker • Sep. 17, 2012

If there's an armchair aquanaut, they will appreciate the view without the goose bumps.

From Seattle Times • Dec. 1, 2011

We found a definite correlation between how many days an aquanaut was sick as a child and how well he performed in Tektite.

From Time Magazine Archive