DASTARD is a 7 letter word that starts with D.

1. \Das"tard\, n. [Prob. from Icel. d[ae]str exhausted.
   breathless, p. p. of d[ae]sa to groan, lose one's breath; cf.
   dasask to become exhausted, and E. daze.]
   One who meanly shrinks from danger; an arrant coward; a
   poltroon.
   
         You are all recreants and dashtards, and delight to
         live in slavery to the nobility.         --Shak.
   
   

2. \Das"tard\, a.
   Meanly shrinking from danger; cowardly; dastardly. ``Their
   dastard souls.'' --Addison.
   
   

3. \Das"tard\, v. t.
   To dastardize. [R.] --Dryden.