luncheon meat vs lunch meat

luncheon meat and lunch meat both are nouns.

Word	Noun	Adjective	Verb	Adverb
luncheon meat	Yes	No	No	No
lunch meat	Yes	No	No	No

As nouns, luncheon meat and lunch meat are synonyms defined as:

luncheon meat and lunch meat: any of various sausages or molded loaf meats sliced and served cold

luncheon meat (noun)	lunch meat (noun)
any of various sausages or molded loaf meats sliced and served cold	any of various sausages or molded loaf meats sliced and served cold