W is the twenty-third letter of the modern Latin alphabet.

W was invented in the 7th century by Anglo-Saxon writers, it was originally a double V (which also represented U—hence its English name "Double U", because the /w/ sound was spelled "vv"). The sound /w/, the voiced labiovelar semivowel, was previously represented by the Runic letter Wynn (Ƿ).

The Latin /w/ sound developed into Romance /v/; therefore V no longer adequately represented Germanic /w/. In German—like in Romance—the phoneme /w/ was lost, this is why German W represents /v/ rather than /w/. In Dutch, W is an approximant (with the exception of words with EEUW, which have [-e:w]).

In the Swedish and Finnish alphabets, "W" is seen as a variant of "V" and not a separate letter. It is however recognised and maintained in names, like "William".

In the alphabets of modern Romance languages, it is not used either, except in foreign names and words recently borrowed (le week-end, il watt, el kiwi). When a spelling for the /w/ sound in a native word is needed, a spelling from the native alphabet, such as U or OU, can be used instead.

The equivalent representation of the /w/ sound in Cyrillics is letter Ў, a unique letter in Belarusian language.

"Double U" is the only English letter name with more than one syllable. This gives the nine-syllable initialism www the irony of being an abbreviation that takes more syllables to say than the unabbreviated form, and thus shortening the "double u" into "dup" only. In Texas dialect, however, the name of W is often condensed to two syllables rather than three.

Whiskey represents the letter W in the NATO phonetic alphabet.

The W on a weather vane stands for west.

Meanings for W

• In biochemistry, W is the symbol for tryptophan.
• In calendars, W is often an abbreviation for Wednesday.
• In chemistry, W is the symbol for tungsten, after its German name, Wolfram.
• In computing,
  • w is a command on Unix systems that displays information on users who are currently logged in.
  • W is the name of a graphical windowing system for Unix platforms; see W Window System.
• In film, W is the name of a 1973 American film; see W (film)
• In journalism, the "five W's" are who, what, when, where and why.
• In the Metric system, W is the symbol for the watt, the SI derived unit for power.
• in physics,
  • W is often the variable for energy or work, measured in joules.
  • W is a kind of a subatomic particle, the W boson.
• In politics, W is a nickname of American President George W. Bush, sometimes spelled out as "Dubya" (the President's name is sometimes written "George Double-U Bush"). "W" is used by Bush himself, on campaign signs, and by many of his supporters. Dubya is generally used by opponents of Bush, or by those making fun of him.
• As the first letter of a postal code,
  • In the United Kingdom, W stands for the West End of London.
• In publishing, W is the name of an American fashion magazine; see W (magazine).
• In radiocommunication, W is one of the ITU prefixes allocated to the United States. W is generally used as the first letter of callsigns allocated to broadcast television or radio stations east of the Mississippi river.
• In television,
  • W is the name of a Canadian digital cable television channel dedicated to women's issues, formerly called WTN; see W Network.
  • W is the name of a television character on the cooking show Good Eats.
• In computing and video games,
  • W is the abbreviation for Wario, a Nintendo character.
  • W is appended to the word "pictures" to form a pornographic meme as in picturesw
  • In the video game Bubble Bobble, golden W's appear on the French fry power-up packages, instead of the Golden Arches (in the form of M's) on McDonald's food containers.

Two-letter combinations starting with W:

• wa wb wc wd we wf wg wh wi wj wk wl wm wn wo wp wq wr ws wt wu wv ww wx wy wz

Letter-digit combinations starting with W:

• W0 W1 W2 W3 W4 W5 W6 W7 W8 W9