dress shirt vs shirt

dress shirt and shirt both are nouns.

Word	Noun	Adjective	Verb	Adverb
dress shirt	Yes	No	No	No
shirt	Yes	No	Yes	No

As nouns, shirt is a hypernym of dress shirt; that is, shirt is a word with a broader meaning than dress shirt:

dress shirt: a man's white shirt (with a starch front) for evening wear (usually with a tuxedo)
shirt: a garment worn on the upper half of the body

dress shirt (noun)	shirt (noun)
a man's white shirt (with a starch front) for evening wear (usually with a tuxedo)	a garment worn on the upper half of the body

dress shirt (verb)	shirt (verb)
	put a shirt on