Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “isotope”


noun [C]    /ˈɑɪ·səˌtoʊp/
physics, chemistry a form of an atom which has a different atomic mass from other forms of the same atom but the same chemical structure
(Definition of isotope noun from the Cambridge Academic Content Dictionary © Cambridge University Press)
Focus on the pronunciation of isotope

Definitions of “isotope” in other dictionaries

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