A Mermanaut is an explorer of the aquatic realm. This exploration may take the form of spiritual, physical, or mental exploration of the planets vast oceans, and the worlds, secrets, and treasures they contain.
The word is a compound of mere, mermaid/man, and naut.
Mere is the Old English word for sea. With the addition of “ma” (merma) both genders of mermaid and merman are represented. Finally, the term "naut" is from nautes (greek: ναύτης), meaning sailor.
A mix of the words "heck" and "hell" just because you are not allowed to say "Hell" in your house because your mom's strict but you're not a baby so you refuse to say "heck"
Human 1: WHAT THE HECLL!
Human 2: What the hell does that mean?
Human 1: Dude, my mom's home don't say that!