all fours vs cinch

all fours and cinch both are nouns.

Word	Noun	Adjective	Verb	Adverb
all fours	Yes	No	No	No
cinch	Yes	No	Yes	No

As nouns, cinch is a hyponym of all fours; that is, cinch is a word with a more specific, narrower meaning than all fours:

all fours: card games in which points are won for taking the high or low or jack or game
cinch: a form of all fours in which the players bid for the privilege of naming trumps

Other hyponyms of all fours include auction pitch, pitch, old sledge, seven-up.

all fours (noun)	cinch (noun)
card games in which points are won for taking the high or low or jack or game	a form of all fours in which the players bid for the privilege of naming trumps
	any undertaking that is easy to do
	stable gear consisting of a band around a horse's belly that holds the saddle in place