Source : Webster's Revised Unabridged Dictionary (1913)

D \D\ (d[=e])
   1. The fourth letter of the English alphabet, and a vocal
      consonant. The English letter is from Latin, which is from
      Greek, which took it from Ph[oe]nician, the probable
      ultimate origin being Egyptian. It is related most nearly
      to t and th; as, Eng. deep, G. tief; Eng. daughter, G.
      tochter, Gr. qyga`thr, Skr. duhitr. See Guide to
      Pronunciation, [root]178, 179, 229.

   2. (Mus.) The nominal of the second tone in the model major
      scale (that in C), or of the fourth tone in the relative
      minor scale of C (that in A minor), or of the key tone in
      the relative minor of F.

   3. As a numeral D stands for 500. in this use it is not the
      initial of any word, or even strictly a letter, but one
      half of the sign ? (or ? ) the original Tuscan numeral for
      1000.

Source : WordNet®

D
     n 1: a fat-soluble vitamin that prevents rickets [syn: {vitamin D},
           {calciferol}, {viosterol}, {ergocalciferol}, {cholecarciferol}]
     2: the cardinal number that is the product of one hundred and
        five [syn: {five hundred}, {500}]
     3: the 4th letter of the Roman alphabet

Source : Free On-Line Dictionary of Computing

D
     
        1. "The Data Language."  {MS-DOS} 4GL.
     
        2. A {Haskell}-like language, with {type class}es.
     
        E-mail: .