| Definition - The French language as used between 900 CE and 1400 CE. Most of it came directly from Vulgar Latin.
1. It was spoken in the northern half of what is now called France, as well as in parts of Belgium and Switzerland. At that time, it was called langue d'oïl to distinguish it from langue d'oc (aka Provencal), which was spoken in southern France.
The Latin vicinum, neighbor, evolved via Vulgar Latin into the Old French voisin.