Source : Webster's Revised Unabridged Dictionary (1913)

Watt \Watt\, n. [From the distinguished mechanician and
   scientist, James Watt.] (Physics)
   A unit of power or activity equal to 10^{7} C.G.S. units of
   power, or to work done at the rate of one joule a second. An
   English horse power is approximately equal to 746 watts.

Source : WordNet®

watt
     n 1: 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: {W}]
     2: Scottish engineer and inventor whose improvements in the
        steam engine led to its wide use in industry (1736-1819)
        [syn: {James Watt}]