speleology vs by-line

speleology and by-line both are nouns.

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

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

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

speleology (noun)	by-line (noun)
the pastime of exploring caves	an auxiliary activity
the scientific study of caves	a line giving the name of the writer of a story or article