arcade vs penny arcade

arcade and penny arcade both are nouns.

Word	Noun	Adjective	Verb	Adverb
arcade	Yes	No	No	No
penny arcade	Yes	No	No	No

As nouns, penny arcade is a hyponym of arcade; that is, penny arcade is a word with a more specific, narrower meaning than arcade:

Other hyponyms of arcade include amusement arcade.

arcade (noun)	penny arcade (noun)
a structure composed of a series of arches supported by columns	an arcade with coin-operated devices for entertainment
a covered passageway with shops and stalls on either side