muster vs gathering

muster and gathering both are nouns.

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

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

Other hypernyms of muster include assemblage.

muster (noun)	gathering (noun)
compulsory military service	the social act of assembling
a gathering of military personnel for duty	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

muster (verb)	gathering (verb)
call to duty, military service, jury duty, etc.
gather or bring together