hobby vs pursuit

hobby and pursuit both are nouns.

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

As nouns, hobby and pursuit are synonyms defined as:

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

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

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

Other hypernyms of hobby include interest, pastime.

hobby (noun)	pursuit (noun)
an auxiliary activity	the act of pursuing in an effort to overtake or capture
small Old World falcon formerly trained and flown at small birds	a diversion that occupies one's time and thoughts (usually pleasantly)
a child's plaything consisting of an imitation horse mounted on rockers; the child straddles it and pretends to ride	an auxiliary activity
	a search for an alternative that meets cognitive criteria