isogloss

A map showing the Uerdingen line, the isogloss between German Low German ik and Central German ich

From iso- +‎ gloss, ultimately from Ancient Greek ἴσος (ísos, “equal”) (possibly from Proto-Indo-European *wi- (“to separate”)) + γλῶσσα (glôssa, “tongue; language”) (ultimately from Proto-Indo-European *glōgʰs).

• (Received Pronunciation) IPA^(key): /ˈaɪsə(ʊ̆)ɡlɒs/
• (General American) IPA^(key): /ˈaɪsəɡlɑs/
• Hyphenation: iso‧gloss

isogloss (plural isoglosses)

1. (sociolinguistics, geography) A line on a map indicating the geographical boundaries of a linguistic feature.

   Synonym: heterogloss

   • 1921, The Calcutta Review, Calcutta: University of Calcutta, OCLC 487321879, page 285:

     Bloch thinks (and we agree with him) that details of isogloss will probably not bear out this kind of grouping.

   • 1970, W[illiam] F[oxwell] Albright; T[homas] O[den] Lambdin, “The Evidence of Language”, in I[orwerth] E[iddon] S[tephen] Edwards, C[yril] J[ohn] Gadd, and N[icholas] G[eoffrey] L[emprière] Hammond, editors, The Cambridge Ancient History, volume I, part 1 (Prolegomena and Prehistory), 3rd edition, Cambridge: Cambridge University Press, published 2000, →ISBN, section IV (Sumerian, Hurrian, Urarṭian, Elamite), page 154:

     There was also a tendency to treat transitive verbs passively, as in Hurrian and Urarṭian; it must, however, be emphasized that this phenomenon may also be considered as an isogloss rather than as an indication of genetic relationship.

   • 2005, Brian D. Joseph, Carol G. Preston, and Dennis R. Preston, editors, Language Diversity in Michigan and Ohio: Towards Two State Linguistic Profiles, Ann Arbor, Mich.: Caravan Books, →ISBN, page 29:

     The convergence of multiple isoglosses on a map, a "bundle", indicates a boundary between one regional dialect and another.

• isolex
• isophone
• Joret line

• isoglossal
• isoglossic

• isograph

• isogloss on Wikipedia.Wikipedia