From 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]

From 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]

From WordNet (r) 2.0:

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]