Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “selenium”


noun [U]     /səˈliː.ni.əm/ (symbol Se)
a chemical element used in photocells and photographic devices and also necessary in small amounts in the bodyChemical elements
(Definition of selenium noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
Focus on the pronunciation of selenium

Definitions of “selenium” in other dictionaries

Translations of “selenium”

Word of the Day


a person or group who receives money, advantages, etc. as a result of something else

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