avocation vs by-line

avocation and by-line both are nouns.

Word	Noun	Adjective	Verb	Adverb
avocation	Yes	No	No	No
by-line	Yes	No	No	No

As nouns, avocation and by-line are synonyms defined as:

Other synonyms of avocation include hobby, pursuit, sideline, spare-time activity.

avocation (noun)	by-line (noun)
an auxiliary activity	an auxiliary activity
	a line giving the name of the writer of a story or article