bowling alley vs skittle alley

bowling alley and skittle alley both are nouns.

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

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

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

Other synonyms of bowling alley include alley.

bowling alley (noun)	skittle alley (noun)
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