tap house vs gin mill

tap house and gin mill both are nouns.

Word	Noun	Adjective	Verb	Adverb
tap house	Yes	No	No	No
gin mill	Yes	No	No	No

As nouns, gin mill is a hyponym of tap house; that is, gin mill is a word with a more specific, narrower meaning than tap house:

tap house: a building with a bar that is licensed to sell alcoholic drinks
gin mill: tavern consisting of a building with a bar and public rooms; often provides light meals

Other hyponyms of tap house include beer garden, bucket shop, pothouse, pub, public house, saloon, taphouse, rathskeller, shebeen.

tap house (noun)	gin mill (noun)
a building with a bar that is licensed to sell alcoholic drinks	tavern consisting of a building with a bar and public rooms; often provides light meals