avocation vs spare-time activity

avocation and spare-time activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
avocation	Yes	No	No	No
spare-time activity	Yes	No	No	No

As nouns, avocation and spare-time activity are synonyms defined as:

Other synonyms of avocation include by-line, hobby, pursuit, sideline.

avocation (noun)	spare-time activity (noun)
an auxiliary activity	an auxiliary activity