snack food vs sandwich

snack food and sandwich both are nouns.

Word	Noun	Adjective	Verb	Adverb
snack food	Yes	No	No	No
sandwich	Yes	No	Yes	No

As nouns, sandwich is a hyponym of snack food; that is, sandwich is a word with a more specific, narrower meaning than snack food:

Other hyponyms of snack food include potato peel, potato peelings, potato skin, chip, crisp, potato chip, Saratoga chip, corn chip.

snack food (noun)	sandwich (noun)
food for light meals or for eating between meals	two (or more) slices of bread with a filling between them

snack food (verb)	sandwich (verb)
	insert or squeeze tightly between two people or objects
	make into a sandwich