Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “uranium”


noun [U] uk   /jʊˈreɪ.ni.əm/ (symbol U) us  
a chemical element that is a heavy, radioactive metal, used in the production of nuclear power and in some types of nuclear weaponChemical elements
(Definition of uranium from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of uranium?
Add Cambridge dictionaries to your browser to your website

Definitions of “uranium” in other dictionaries

Word of the Day


an alcoholic drink made from apples

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