Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “atomic mass unit”

atomic mass unit

noun [C]    /əˈtɑm·ɪk ˈmæs ˌju·nɪt/
chemistry, physics one-twelfth the mass of one atom of carbon
(Definition of atomic mass unit noun from the Cambridge Academic Content Dictionary © Cambridge University Press)
Focus on the pronunciation of atomic mass unit

Definitions of “atomic mass unit” in other dictionaries

Translations of “atomic mass unit”

Word of the Day


the skill or activity of preparing and cooking food

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