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femtometer

American  
[fem-tuh-mee-ter] / ˈfɛm təˌmi tər /

noun

Physics.

  1. fermi. fm

Etymology

Origin of femtometer

First recorded in 1970–75; femto- + meter 1

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The detectors must also squelch other vibrations to stabilize the length of each arm to 1 femtometer, the width of a proton.

From Science Magazine • May 16, 2023

The team’s measurement of the proton’s radius was 0.73 femtometer, even smaller than the 0.84-femtometer electric charge radius.

From Scientific American • Mar. 16, 2023

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.