W W /ˈdʌbəljuː/

noun

1. The 23rd letter of the Roman alphabet  ( double-u , W )
   the 23rd letter of the Roman alphabet
   
2. 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  ( W , watt )
   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
   
3. The cardinal compass point that is a 270 degrees  ( due west , W , westward , west )
   the cardinal compass point that is a 270 degrees
    Sail west, and you'll eventually reach the island.
   Sail west, and you'll eventually reach the island.
   
   
4. 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  ( atomic number 74 , W , wolfram , tungsten )
   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
    Tungsten bulbs are commonly used in older lamps.
   Tungsten bulbs are commonly used in older lamps.