isochalaz vs isopleth

isochalaz and isopleth both are nouns.

Word	Noun	Adjective	Verb	Adverb
isochalaz	Yes	No	No	No
isopleth	Yes	No	No	No

As nouns, isopleth is a hypernym of isochalaz; that is, isopleth is a word with a broader meaning than isochalaz:

isochalaz: a line indicating a constant frequency of hail storms.
isopleth: a line drawn on a map connecting points having the same numerical value of some variable

Other hypernyms of isochalaz include isarithm, isogram.

isochalaz (noun)	isopleth (noun)
a line indicating a constant frequency of hail storms.	a line drawn on a map connecting points having the same numerical value of some variable