gathering vs aggregation

gathering and aggregation both are nouns.

Word	Noun	Adjective	Verb	Adverb
gathering	Yes	No	No	No
aggregation	Yes	No	No	No

As nouns, aggregation is a hypernym of gathering; that is, aggregation is a word with a broader meaning than gathering:

Other hypernyms of gathering include assembling, collecting, collection.

gathering (noun)	aggregation (noun)
the social act of assembling	the act of gathering something together
the act of gathering something	several things grouped together or considered as a whole
sewing consisting of small folds or puckers made by pulling tight a thread in a line of stitching
a group of persons together in one place