Source : Webster's Revised Unabridged Dictionary (1913)

Dreadnaught \Dread"naught`\, n.
   1. A fearless person.

   2. Hence: A garment made of very thick cloth, that can defend
      against storm and cold; also, the cloth itself;
      fearnaught.

Source : WordNet®

dreadnaught
     n : battleship that has big guns all of the same caliber [syn: {dreadnought}]