Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “unknown quantity”

unknown quantity

noun [C usually singular]    
C2 a person or a thing whose abilities , powers , or effects are not yet known : The third candidate for the party leadership is a relatively unknown quantity .Unknown and unfamiliar
(Definition of unknown quantity noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
Focus on the pronunciation of unknown quantity

Translations of “unknown quantity”

Word of the Day


to pour liquid slowly over something, especially in a thin line or in small drops

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