Search Result for "plutonium 239":
Wordnet 3.0

NOUN (1)

1. a highly fissionable isotope of plutonium that is used in atomic weapons and as a reactor fuel; produced by irradiating uranium 238 with slow electrons; 



WordNet (r) 3.0 (2006):

plutonium 239
    n 1: a highly fissionable isotope of plutonium that is used in
         atomic weapons and as a reactor fuel; produced by
         irradiating uranium 238 with slow electrons