speleology vs sideline

speleology and sideline both are nouns.

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

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

Other hypernyms of speleology include avocation, by-line, hobby, pursuit, spare-time activity.

speleology (noun)	sideline (noun)
the pastime of exploring caves	an auxiliary activity
the scientific study of caves	an auxiliary line of merchandise
	a line that marks the side boundary of a playing field

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