western sandwich vs western

western sandwich and western both are nouns.

Word	Noun	Adjective	Verb	Adverb
western sandwich	Yes	No	No	No
western	Yes	Yes	No	No

As nouns, western sandwich and western are synonyms defined as:

western sandwich (noun)	western (noun)
a sandwich made from a western omelet	a sandwich made from a western omelet

western sandwich (adjective)	western (adjective)
	relating to or characteristic of the western parts of the world or the West as opposed to the eastern or oriental parts
	of or characteristic of regions of the United States west of the Mississippi River
	lying toward or situated in the west
	of wind; from the west