snorkel vs sub

snorkel and sub both are nouns.

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

snorkel (noun)	sub (noun)
air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time	a submersible warship usually armed with torpedoes
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	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

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