Source : Webster's Revised Unabridged Dictionary (1913)

W \W\ (d[u^]b"'l [=u]),
   the twenty-third letter of the English alphabet, is usually a
   consonant, but sometimes it is a vowel, forming the second
   element of certain diphthongs, as in few, how. It takes its
   written form and its name from the repetition of a V, this
   being the original form of the Roman capital letter which we
   call U. Etymologically it is most related to v and u. See V,
   and U. Some of the uneducated classes in England, especially
   in London, confuse w and v, substituting the one for the
   other, as weal for veal, and veal for weal; wine for vine,
   and vine for wine, etc. See Guide to Pronunciation,
   [sect][sect] 266-268.

Source : WordNet®

W
     n 1: a heavy gray-white metallic element; the pure form is used
          mainly in electrical applications; it is found in
          several ores including wolframite and scheelite [syn: {tungsten},
           {wolfram}, {atomic number 74}]
     2: the cardinal compass point that is a 270 degrees [syn: {west},
         {due west}]
     3: a unit of power equal to 1 joule per second; the power
        dissipated by a current of 1 ampere flowing across a
        resistance of 1 ohm [syn: {watt}]
     4: the 23rd letter of the Roman alphabet [syn: {double-u}]