Joret line

Etymology
First identified by Charles Joret and published in 1883.

Proper noun

 * 1)  An isogloss used in the linguistics of the langues d'oïl. Dialects north of the line have preserved Vulgar Latin /k/ and /ɡ/ before /a/; dialects south of the line have palatalized /k/ and /ɡ/ before /a/.