An isogloss is the geographical boundary of a certain linguistic feature, e.g. the pronunciation of a vowel, the meaning of a word, or use of some syntactic feature. Major dialects are typically demarcated by whole bundles of isoglosses, e.g. the Benrath line that divides High German and Low Saxon-Low Franconian; or the La Spezia-Rimini Line which divides the eastern Romance languages from the western ones. Undoubtedly, the largest well-known isogloss is the Centum-Satem isogloss, which traditionally separates the Indo-European languages into two distinct genetic categories.

The name is inspired by contour lines such as isobar, etc.; however, the isogloss separates rather than connects points of equal language (perhaps one could say it connects points of indefinite language).

Linguistics

Isoglos | Isoglosse | Isogloss | Изоглоса | Изоглосса | Isoglosse | Ισόγλωσσο | Isoglosa | Isoglosse | Isoglosa | Isoglos | Izoglossza | Isoglosse | 等語線 | Isoglossa | Isoglosă | Isoglossa | Isogloss | 同言綫