escape hatch vs sub

escape hatch and sub both are nouns.

Word	Noun	Adjective	Verb	Adverb
escape hatch	Yes	No	No	No
sub	Yes	No	Yes	No

escape hatch (noun)	sub (noun)
hatchway that provides a means of escape in an emergency	a submersible warship usually armed with torpedoes
	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

escape hatch (verb)	sub (verb)
	be a substitute