fissile

American  

[fis-uhl] / ˈfɪs əl /

adjective

1. capable of being split or divided; cleavable.

2. Physics.

   1. fissionable.

   2. (of a nuclide) capable of undergoing fission induced by low-energy neutrons, as uranium 233 and 235.

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fissile British  

/ ˈfɪsaɪl /

adjective

1. capable of undergoing nuclear fission as a result of the impact of slow neutrons

2. another word for fissionable

3. tending to split or capable of being split

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Other Word Forms

• fissility
  noun
• nonfissility
  noun
• nonfissile
  adjective
• unfissile
  adjective

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Etymology

Origin of fissile

1655–65; < Latin fissilis, equivalent to fiss ( us ) ( see fissi-) + -ilis -ile

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Example Sentences

See Examples For:

fissile

But the fissile material required to build nuclear weapons remains in the country, under the watch of U.S. satellite surveillance.

From Los Angeles Times ● Jul. 21, 2026

North Korea currently has an estimated 60 nuclear warheads, plus enough fissile material to make at least 90 more, according to a new estimate by the Stockholm International Peace Research Institute.

From The Wall Street Journal ● Jun. 10, 2026

"Beijing is on track to have the fissile material necessary for more than 1,000 nuclear warheads by 2030," Yeaw said.

From Barron's ● Feb. 23, 2026

The Comprehensive Nuclear Test Ban Treaty of 1996 allows activities to assure the safety and reliability of nuclear weapons, including experiments involving fissile material, as long as they don’t result in a nuclear-explosive yield.

From The Wall Street Journal ● Feb. 6, 2026

While the Mark I was still undergoing this shakedown procedure, Lawrence spent his time soothing official doubts about the MTA by citing the continuing threat of a shortage of fissile material.

From "Big Science" by Michael Hiltzik

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