Walloon (adj.)

1520s, of a people of what is now souther and southeastern Belgium, also of their language, from Middle French Wallon, literally "foreigner," of Germanic origin (compare Old High German walh "foreigner"). The people are of Gaulish origin and speak a French dialect. The name is a form of the common appellation of Germanic peoples to Romanic-speaking neighbors. See Vlach, also Welsh. As a noun from 1560s; as a language name from 1640s.