isoclinic line vs isarithm

isoclinic line and isarithm both are nouns.

Word	Noun	Adjective	Verb	Adverb
isoclinic line	Yes	No	No	No
isarithm	Yes	No	No	No

As nouns, isarithm is a hypernym of isoclinic line; that is, isarithm is a word with a broader meaning than isoclinic line:

isoclinic line: an isogram connecting points of equal magnetic inclination
isarithm: a line drawn on a map connecting points having the same numerical value of some variable

Other hypernyms of isoclinic line include isogram, isopleth.

isoclinic line (noun)	isarithm (noun)
an isogram connecting points of equal magnetic inclination	a line drawn on a map connecting points having the same numerical value of some variable