The Collaborative International Dictionary of English v.0.48:

Labial \La"bi*al\, n.
   1. (Phonetics) A letter or character representing an
      articulation or sound formed or uttered chiefly with the
      lips, as b, p, w.
      [1913 Webster]

   2. (Mus.) An organ pipe that is furnished with lips; a flue
      pipe.
      [1913 Webster]

   3. (Zool.) One of the scales which border the mouth of a fish
      or reptile.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

WordNet (r) 3.0 (2006):

W
    n 1: a heavy grey-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, W, atomic number 74]
    2: the cardinal compass point that is a 270 degrees [syn:
       west, due west, westward, W]
    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, W]
    4: the 23rd letter of the Roman alphabet [syn: W, w,
       double-u]

The Devil's Dictionary (1881-1906):

W (double U) has, of all the letters in our alphabet, the only
cumbrous name, the names of the others being monosyllabic.  This
advantage of the Roman alphabet over the Grecian is the more valued
after audibly spelling out some simple Greek word, like
_epixoriambikos_.  Still, it is now thought by the learned that other
agencies than the difference of the two alphabets may have been
concerned in the decline of "the glory that was Greece" and the rise
of "the grandeur that was Rome."  There can be no doubt, however, that
by simplifying the name of W (calling it "wow," for example) our
civilization could be, if not promoted, at least better endured.