Why is the ninth month called September?
late Old English pryto, Kentish prede, Mercian pride "pride, haughtiness, pomp," from prud (see proud). There is debate whether Scandinavian cognates (Old Norse pryði, Old Swedish prydhe , Danish pryd, etc.) are borrowed from Old French (from Germanic) or from Old English. Meaning "that which makes a person or people most proud" is from c.1300. First applied to groups of lions late 15c., but not commonly so used until c.1930. Paired with prejudice from 1610s.
mid-12c. in the reflexive sense "congratulate (oneself), be proud," c.1200 as "be arrogant, act haughtily," from pride (n.). Related: Prided; priding.