W (Noun) — The 23rd letter of the Roman alphabet.
W (Noun) — The cardinal compass point that is a 270 degrees.
W (Noun) — 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.
W (Noun) — 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 (Noun) — (physics) a short-lived charged elementary particle that mediates the weak force.