Merriam-Webster Collegiate Dictionary - brash

 I. adjective  Etymology: origin unknown  Date: 1566  1. brittle ~ wood  2.  a. heedless of the consequences ; audacious a ~ adventurer  b. done in haste without regard for consequences ; rash ~ acts  3.  a. full of fresh raw vitality a ~ frontier town  b. uninhibitedly energetic or demonstrative ; bumptious a ~ comedian  4.  a. lacking restraint and discernment ; tactless ~ remarks  b. aggressively self-assertive ; impudent ~ to the point of arrogance  5. piercingly sharp ; harsh a ~ squeal of brakes  6. marked by vivid contrast ; bold ~ colors  • ~ly adverb  • ~ness noun  II. noun  Etymology: obsolete English ~ to breach a wall  Date: 1787 a mass of fragments (as of ice)