food market vs market place

food market and market place both are nouns.

Word	Noun	Adjective	Verb	Adverb
food market	Yes	No	No	No
market place	Yes	No	No	No

As nouns, market place is a hypernym of food market; that is, market place is a word with a broader meaning than food market:

food market: a marketplace where groceries are sold
market place: an area in a town where a public mercantile establishment is set up

Other hypernyms of food market include market, marketplace, mart.

food market (noun)	market place (noun)
a marketplace where groceries are sold	the world of commercial activity where goods and services are bought and sold
	an area in a town where a public mercantile establishment is set up