Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “fission”


noun [U]     /ˈfɪʃ.ən/
specialized physics the process of dividing the nucleus of an atom , which results in the release of a large amount of energy : nuclear fissionCellsPhysical and chemical processes specialized biology the division of a living cell as part of reproduction : The fission of the cell could be inhibited with certain chemicals .
(Definition of fission noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
Focus on the pronunciation of fission

More definitions for “fission”

Definitions of “fission” in other dictionaries

Word of the Day

best man

a male friend or relation of the bridegroom who stands with him and helps him during a marriage ceremony

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