Merriam-Webster Collegiate Dictionary - cavalier

 I. noun  Etymology: Middle French, from Old Italian ~e, from Old Occitan ~, from Late Latin caballarius horseman, from Latin caballus  Date: 1589  1. a gentleman trained in arms and horsemanship  2. a mounted soldier ; knight  3. capitalized an adherent of Charles I of England  4. gallant  II. adjective  Date: circa 1641  1. debonair  2. marked by or given to offhand and often disdainful dismissal of important matters a ~ attitude toward money  3.  a. capitalized of or relating to the party of Charles I of England in his struggles with the Puritans and Parliament  b. aristocratic  c. capitalized of or relating to the English Cavalier poets of the mid-17th century  • ~ism noun  • ~ly adverb