skittle alley vs bowling alley

skittle alley and bowling alley both are nouns.

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

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

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

Other synonyms of skittle alley include alley.

skittle alley (noun)	bowling 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