Definition of fissile in English:

fissile

adjective

  • 1(of an atom or element) able to undergo nuclear fission:

    ‘a fissile isotope’
    • ‘As a general rule, however, the biggest hurdle for a would-be nuclear power is the acquisition of fissile material - enriched uranium or plutonium.’
    • ‘No natural reactors exist today, as the relative density of fissile uranium has now decayed below that needed for a sustainable reaction.’
    • ‘It resumed the production, and testing of uranium enrichment centrifuges that can make fissile material for nuclear reactors or weapons.’
    • ‘It also is the toxic and radioactive byproduct of enriched uranium, the fissile material in nuclear weapons.’
    • ‘Smuggling can potentially provide fissile material for nuclear weapons or a wider range of radioactive materials for use in ‘dirty bombs’.’
  • 2(chiefly of rock) easily split:

    ‘flat-bedded and very highly fissile shale’
    • ‘The fossiliferous horizons occur in greenish to greyish siltstones and brown to black fissile shales associated with mollusc shells.’
    • ‘For example, fissile slates tend to yield much flatter particles than massive granites.’
    • ‘This horizon, up to 1.3 m thick, is a black, highly fissile shale.’
    • ‘The oil shales are very fissile, non-laminated, dark brown to black and have a bituminous smell, whereas the less carbonaceous beds are weakly fissile.’
    • ‘The shales are conspicuously fissile throughout the section and, along with the associated carbonates, tend to become increasingly red-colored toward the top of the member.’

Origin

Mid 17th century (in the sense ‘easily split’): from Latin fissilis, from fiss- split, cracked, from the verb findere.

Pronunciation:

fissile

/ˈfɪsʌɪl/