Langue d'oc was truer to Latin than Old French or Castilian Spanish were, and had fewer Germanic words. Dante considered it a separate language, and it and the northern French were not always mutually intelligible. Jonathan Sumption's "The Albigensian Crusade" [Faber and Faber, 1978] refers to a court official at Albi "who in 1228 referred to a seal as bearing an inscription in 'French or some other foreign language.'" The French authorities began to repress langue d'oc in 16c.
"Old or modern Provençal; langue d'Oc," 1940, also "the northern variant of modern Provençal;" from French oc, the word used south of the Loire for "yes" (see Languedoc).
Modern French for "yes," from Old French oïl "yes," at first two words meaning "yes, he," or "yes, they," which gradually came to mean simply "yes." From the Latin phrase hoc ille "yes," literally "this he, so he" (did or said).
The French originally said "yes, I," "yes, you," "yes, we," etc., where the pronoun was the subject of an unexpressed verb easily supplied from the question. [C.H.C. Wright, "A History of French Literature," Haskell House, 1969]
Thus the o is from Latin hoc "this," and the rest of the word is from the Latin personal pronoun ille "he" (in Vulgar Latin illi which is also "they"). Old French also had o alone as "yes." Compare Languedoc.
1570s, "religious puritan" (implied in Catharism), from Medieval Latin Cathari "the Pure," name taken by Novatians and other Christian sects, from New Testament Greek katharizein "to make clean," from Greek katharos "pure" (see catharsis). Especially in reference to the 12c. sects (Albigenses, etc.) in Languedoc and the Piedmont that denied the authority of Rome. Related: Catharist.
"Black friar, one of an order of mendicant preaching friars," 1630s, from Latin form of the name of Domingo de Guzman (Santo Domingo), who founded the order in Languedoc. They were confirmed by the pope in 1216. His name, like Italian form Dominic (q.v.), is from Latin dominicus,which in Christian use meant "devoted to the Lord."
c. 1600, "relating to the Albigenses," collective name for the Catharist religious reformers of southern France c. 1020-1250, from Medieval Latin Albigenses (12c.), from French Albi, name of the town in Languedoc where they lived and first were condemned as heretics (1176) and vigorously persecuted (the Albigensian Crusade). The town name is from Roman personal name Albius, from Latin albus "white" (see alb). Also sometimes Albanesian.
c. 1610s, "legal quibbling, sophistry, mean or petty tricks," from French chicanerie "trickery," from chicaner "to pettifog, quibble" (15c.), which is of unknown origin, perhaps from Middle Low German schikken "to arrange, bring about," or from the name of a golf-like game once played in Languedoc. Also compare French chic "small, little," as a noun "a small piece; finesse, subtlety." Thornton's "American Glossary" has shecoonery (1845), which it describes as probably a corruption of chicanery.