The Collaborative International Dictionary of English v.0.48:

Craven \Cra"ven\ (kr?"v'n), a. [OE. cravant, cravaunde, OF.
   cravant? struck down, p. p. of cravanter, crevanter, to
   break, crush, strike down, fr. an assumed LL. crepantare, fr.
   L. crepans, p. pr. of crepare to break, crack, rattle. Cf.
   Crevice, Crepitate.]
   Cowardly; fainthearted; spiritless. "His craven heart."
   --Shak.
   [1913 Webster]

         The poor craven bridegroom said never a word. --Sir. W.
                                                  Scott.
   [1913 Webster]

         In craven fear of the sarcasm of Dorset. --Macaulay.
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The Collaborative International Dictionary of English v.0.48:

Craven \Cra"ven\, n. [Formerly written also cravant and
   cravent.]
   A recreant; a coward; a weak-hearted, spiritless fellow. See
   Recreant, n.
   [1913 Webster]

         King Henry. Is it fit this soldier keep his oath?
         Fluellen. He is a craven and a villain else. --Shak.

   Syn: Coward; poltroon; dastard.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Craven \Cra"ven\, v. t. [imp. & p. p. Cravened (-v'nd); p. pr.
   & vb. n. Cravening.]
   To make recreant, weak, spiritless, or cowardly. [Obs.]
   [1913 Webster]

         There is a prohibition so divine,
         That cravens my weak hand.               --Shak.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

19 Moby Thesaurus words for "craven":
   base, caitiff, chicken, coward, dastard, dastardly, dunghill,
   dunghilly, funk, funker, gutless, lily-livered, poltroon,
   poltroonish, pusillanimous, quitter, recreant, spunkless,
   unmanly