: a former SI unit of length equal to 10−15 meters : femtometer

Word History


Enrico Fermi

First Known Use

1955, in the meaning defined above

Time Traveler
The first known use of fermi was in 1955

Dictionary Entries Near fermi

Cite this Entry

“Fermi.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fermi. Accessed 23 Jun. 2024.

Biographical Definition


biographical name

Fer·​mi ˈfer-(ˌ)mē How to pronounce Fermi (audio)
Enrico 1901–1954 American (Italian-born) physicist
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