fowl run vs chicken yard

fowl run and chicken yard both are nouns.

Word	Noun	Adjective	Verb	Adverb
fowl run	Yes	No	No	No
chicken yard	Yes	No	No	No

As nouns, fowl run and chicken yard are synonyms defined as:

Other synonyms of fowl run include chicken run, hen yard.

fowl run (noun)	chicken yard (noun)
an enclosed yard for keeping poultry	an enclosed yard for keeping poultry