agglomerate vs aggregation

agglomerate and aggregation both are nouns.

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

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

Other hypernyms of agglomerate include accumulation, assemblage, collection.

agglomerate (noun)	aggregation (noun)
a collection of objects laid on top of each other	the act of gathering something together
volcanic rock consisting of large fragments fused together	several things grouped together or considered as a whole

agglomerate (adjective)	aggregation (adjective)
clustered together but not coherent

agglomerate (verb)	aggregation (verb)
form into one cluster