old sledge vs seven-up

old sledge and seven-up both are nouns.

Word	Noun	Adjective	Verb	Adverb
old sledge	Yes	No	No	No
seven-up	Yes	No	No	No

As nouns, old sledge and seven-up are synonyms defined as:

old sledge and seven-up: a form of all fours in which a total of seven points is game

old sledge (noun)	seven-up (noun)
a form of all fours in which a total of seven points is game	a form of all fours in which a total of seven points is game