Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “W”


written abbreviation for watt (= a unit for measuring electrical power): a 40W light bulbUnits of electrical power
(Definition of W from the Cambridge Learner's Dictionary © Cambridge University Press)

More Learner's Dictionary definitions for “W”

Translations of “W”

Word of the Day


friendly or helpful

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More