conning tower vs sub

conning tower and sub both are nouns.

Word	Noun	Adjective	Verb	Adverb
conning tower	Yes	No	No	No
sub	Yes	No	Yes	No

conning tower (noun)	sub (noun)
a raised bridge on a submarine; often used for entering and exiting	a submersible warship usually armed with torpedoes
an armored pilothouse on a warship	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

conning tower (verb)	sub (verb)
	be a substitute