long suit vs accumulation

long suit and accumulation both are nouns.

Word	Noun	Adjective	Verb	Adverb
long suit	Yes	No	No	No
accumulation	Yes	No	No	No

As nouns, accumulation is a hypernym of long suit; that is, accumulation is a word with a broader meaning than long suit:

Other hypernyms of long suit include aggregation, assemblage, collection.

long suit (noun)	accumulation (noun)
an asset of special worth or utility	the act of accumulating
in a hand, the suit having the most cards	several things grouped together or considered as a whole
	(finance) profits that are not paid out as dividends but are added to the capital base of the corporation
	an increase by natural growth or addition