year vs gathering

year and gathering both are nouns.

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

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

Other hypernyms of year include assemblage.

year (noun)	gathering (noun)
a body of students who graduate together	the social act of assembling
the period of time that it takes for a planet (as, e.g., Earth or Mars) to make a complete revolution around the sun	the act of gathering something
a period of time containing 365 (or 366) days	sewing consisting of small folds or puckers made by pulling tight a thread in a line of stitching
a period of time occupying a regular part of a calendar year that is used for some particular activity	a group of persons together in one place