sideline vs pursuit

sideline and pursuit both are nouns.

Word	Noun	Adjective	Verb	Adverb
sideline	Yes	No	Yes	No
pursuit	Yes	No	No	No

As nouns, sideline and pursuit are synonyms defined as:

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

As nouns, pursuit is a hypernym of sideline; that is, pursuit is a word with a broader meaning than sideline:

sideline: an auxiliary activity
pursuit: a diversion that occupies one's time and thoughts (usually pleasantly)

Other hypernyms of sideline include interest, pastime.

sideline (noun)	pursuit (noun)
an auxiliary activity	the act of pursuing in an effort to overtake or capture
an auxiliary line of merchandise	a diversion that occupies one's time and thoughts (usually pleasantly)
a line that marks the side boundary of a playing field	an auxiliary activity
	a search for an alternative that meets cognitive criteria

sideline (verb)	pursuit (verb)
remove from the center of activity or attention; place into an inferior position