langue d'oïl

noun

läŋ-ˈdȯi(-ə)l  -ˈdȯi 

läⁿg-dȯ-ˈēl,

-ˈdȯi

: french sense 2

Word History

Etymology

French, from Old French, literally, language of oïl; from the French use of the word oïl for "yes"

First Known Use

circa 1682, in the meaning defined above