Frogman
Part of speech: noun
Definition: A diver, especially one in a diving suit (as opposed to one in scuba gear). A US Navy SEAL.
Diver
Part of speech: noun
Definition: someone who dives, especially as a sportsomeone who works underwater; a frogmanthe loon (bird)The New Zealand sand diverThe Long-finned sand diver
Example sentence: As every scuba diver knows, panic is your worst enemy: when it hits, your mind starts to thrash and you are likely to do something really stupid and self-destructive.