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• fermi
  fermi

  noun

  a unit of length, 10− 15 m, used in measuring nuclear distances. F
• Fermi
  Fermi

  noun

  Enrico 1901–54, Italian physicist, in the U.S. after 1939: Nobel Prize 1938.

fermi

¹ American  

[fur-mee, fer-mee] / ˈfɜr mi, ˈfɛr mi /

noun

Physics.

1. a unit of length, 10− 15 m, used in measuring nuclear distances. F

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Fermi ² American  

[fur-mee, fer-mee] / ˈfɜr mi, ˈfɛr mi /

noun

1. Enrico 1901–54, Italian physicist, in the U.S. after 1939: Nobel Prize 1938.

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fermi ¹ British  

/ ˈfɜːmɪ /

noun

1. a unit of length used in nuclear physics equal to 10 ^–15 metre

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Fermi ² British  

/ ˈfɜːmɪ, ˈfɛrmi /

noun

1. Enrico (enˈriːko). 1901-54, Italian nuclear physicist, in the US from 1939. He was awarded a Nobel prize for physics in 1938 for his work on radioactive substances and nuclear bombardment and headed the group that produced the first controlled nuclear reaction (1942)

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Fermi Scientific  

/ fĕr′mē /

1. Italian-born American physicist who won a 1938 Nobel Prize for his research on neutrons. In 1942, with Leo Szilard, Fermi built the world's first nuclear reactor. He also discovered over 40 new isotopes, including the element fermium, which is named for him.

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Etymology

Origin of fermi

Named after E. Fermi

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Example Sentences

See Examples For:

fermi Fermi

First, we must calculate the time Δt that the pion exists, given that the distance it travels at nearly the speed of light is about 1 fermi.

From Textbooks ● Aug. 12, 2015

Why is it that the electron seems to have no size other than its wavelength, while the proton and neutron are about 1 fermi in size?

From Textbooks ● Aug. 12, 2015

I reserve for you some canti fermi and antiphons, which I wrote down at the time, and my little book describes the order of the various services and the meaning of the different ceremonies.

From Letters of Felix Mendelssohn Bartholdy from Italy and Switzerland by Felix Mendelssohn-Bartholdy

In very pure metals, these Landau levels can repeatedly pass through the Fermi level, the energy boundary between occupied and unoccupied electronic states.

From Science Daily ● Sep. 5, 2026

Fermi also said Hillcore Energy Capital will build, own and operate 2.6 gigawatts of power generation—mostly natural gas with some solar and battery storage—at Project Matador.

From The Wall Street Journal ● Aug. 13, 2026

Fermi announces a $6.5 billion lease contract with AI cloud provider TensorWave.

From Barron's ● Aug. 11, 2026

In December 1942, physicist Enrico Fermi set off humanity’s first nuclear chain reaction, in a squash court at the University of Chicago.

From The Wall Street Journal ● Jul. 28, 2026

In this cave, Heisenberg had been trying to build an atomic pile, similar to the one made by Enrico Fermi on the squash court in Chicago.

From "Bomb" by Steve Sheinkin

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