isolex vs isogloss

isolex and isogloss both are nouns.

Word	Noun	Adjective	Verb	Adverb
isolex	Yes	No	No	No
isogloss	Yes	No	No	No

As nouns, isogloss is a hypernym of isolex; that is, isogloss is a word with a broader meaning than isolex:

isolex: an isogloss marking off the area in which a particular item of vocabulary is found.
isogloss: the locative boundary of a certain linguistic feature, such as the pronunciation of a vowel, the meaning of a word, or use of some syntactic feature.

Other hypernyms of isolex include heterogloss.

isolex (noun)	isogloss (noun)
an isogloss marking off the area in which a particular item of vocabulary is found.	the locative boundary of a certain linguistic feature, such as the pronunciation of a vowel, the meaning of a word, or use of some syntactic feature.