sub vs snorkel

sub and snorkel both are nouns.

Word	Noun	Adjective	Verb	Adverb
sub	Yes	No	Yes	No
snorkel	Yes	No	Yes	No

sub (noun)	snorkel (noun)
a submersible warship usually armed with torpedoes	air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time
a large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States	breathing device consisting of a bent tube fitting into a swimmer's mouth and extending above the surface; allows swimmer to breathe while face down in the water

sub (verb)	snorkel (verb)
be a substitute	dive with a snorkel