mobilization vs gathering

mobilization and gathering both are nouns.

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

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

mobilization: act of marshaling and organizing and making ready for use or action
gathering: the social act of assembling

Other hypernyms of mobilization include assemblage, assembly.

mobilization (noun)	gathering (noun)
act of marshaling and organizing and making ready for use or action	the social act of assembling
act of assembling and putting into readiness for war or other emergency:	the act of gathering something
	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