social gathering vs social occasion

social gathering and social occasion both are nouns.

Word	Noun	Adjective	Verb	Adverb
social gathering	Yes	No	No	No
social occasion	Yes	No	No	No

As nouns, social gathering and social occasion are synonyms defined as:

social gathering and social occasion: a formal or official social gathering or ceremony of people

Other synonyms of social gathering include affair, function, occasion, social affair, social function.

social gathering (noun)	social occasion (noun)
a formal or official social gathering or ceremony of people	a formal or official social gathering or ceremony of people