The Collaborative International Dictionary of English v.0.48:

Coward \Cow"ard\ (kou"?rd), a. [OF. couard, coard, coart, n. and
   adj., F. couard, fr. OF. coe, coue, tail, F. queue (fr. L.
   coda, a form of cauda tail) + -ard; orig., short-tailed, as
   an epithet of the hare, or perh., turning tail, like a scared
   dog. Cf. Cue, Queue, Caudal.]
   1. (Her.) Borne in the escutcheon with his tail doubled
      between his legs; -- said of a lion.
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   2. Destitute of courage; timid; cowardly.
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            Fie, coward woman, and soft-hearted wretch. --Shak.
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   3. Belonging to a coward; proceeding from, or expressive of,
      base fear or timidity.
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            He raised the house with loud and coward cries.
                                                  --Shak.
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            Invading fears repel my coward joy.   --Proir.
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The Collaborative International Dictionary of English v.0.48:

Coward \Cow"ard\, n.
   A person who lacks courage; a timid or pusillanimous person;
   a poltroon.
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         A fool is nauseous, but a coward worse.  --Dryden.

   Syn: Craven; poltroon; dastard.
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The Collaborative International Dictionary of English v.0.48:

Coward \Cow"ard\, v. t.
   To make timorous; to frighten. [Obs.]
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         That which cowardeth a man's heart.      --Foxe.
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WordNet (r) 3.0 (2006):

coward
    n 1: a person who shows fear or timidity
    2: English dramatist and actor and composer noted for his witty
       and sophisticated comedies (1899-1973) [syn: Coward, Noel
       Coward, Sir Noel Pierce Coward]

The Devil's Dictionary (1881-1906):

COWARD, n.  One who in a perilous emergency thinks with his legs.