atomic bomb
Americannoun
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a bomb whose potency is derived from nuclear fission of atoms of fissionable material with the consequent conversion of part of their mass into energy.
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a bomb whose explosive force comes from a chain reaction based on nuclear fission in U-235 or plutonium.
noun
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A very destructive bomb that derives its explosive power from the fission of atomic nuclei. Atomic bombs usually have plutonium 239 or uranium 235 as their fissionable material.
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Also called atom bomb
Etymology
Origin of atomic bomb
First recorded in 1910–15
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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.
Iran denies seeking a nuclear weapon and the UN nuclear watchdog says that an atomic bomb was not imminent before the war.
From Barron's • Apr. 23, 2026
In 1943 the Quebec Agreement formalized a collaboration between British and American scientists who would build the atomic bomb.
From The Wall Street Journal • Mar. 23, 2026
America built the atomic bomb when the physics seemed impossible.
From The Wall Street Journal • Dec. 1, 2025
The US tested the first atomic bomb in July 1945 in the desert at Alamogordo, New Mexico.
From BBC • Oct. 30, 2025
For the physicists of the atomic bomb program, Germany’s surrender on May 7, 1945, complicated the moral and ethical issues connected with the device they had invented.
From "Big Science" by Michael Hiltzik
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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.