D defs.my
Entry 1 sense Webster, 1913

fissionable

/fĭsh'-ən-əb-əl/ · fis·sion·able · IPA /fˈɪʃənəbəl/
01 a. Capable of undergoing nuclear fission; -- a property of certain isotopes of elements with heavy nuclei.
  1. 1.
    Capable of undergoing nuclear fission; -- a property of certain isotopes of elements with heavy nuclei.
Syn. fissile.