alley vs bowling alley

alley and bowling alley both are nouns.

Word	Noun	Adjective	Verb	Adverb
alley	Yes	No	No	No
bowling alley	Yes	No	No	No

As nouns, alley and bowling alley are synonyms defined as:

alley and bowling alley: a lane down which a bowling ball is rolled toward pins

Other synonyms of alley include skittle alley.

alley (noun)	bowling alley (noun)
a narrow street with walls on both sides	a lane down which a bowling ball is rolled toward pins
a lane down which a bowling ball is rolled toward pins	a building that contains several alleys for bowling