isopleth vs isogram

isopleth and isogram both are nouns.

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

As nouns, isopleth and isogram are synonyms defined as:

isopleth and isogram: a line drawn on a map connecting points having the same numerical value of some variable

Other synonyms of isopleth include isarithm.

isopleth (noun)	isogram (noun)
a line drawn on a map connecting points having the same numerical value of some variable	a line drawn on a map connecting points having the same numerical value of some variable