expo vs accumulation

expo and accumulation both are nouns.

Word	Noun	Adjective	Verb	Adverb
expo	Yes	No	No	No
accumulation	Yes	No	No	No

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

expo: a collection of things (goods or works of art etc.) for public display
accumulation: several things grouped together or considered as a whole

Other hypernyms of expo include aggregation, assemblage, collection.

expo (noun)	accumulation (noun)
a collection of things (goods or works of art etc.) for public display	the act of accumulating
	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