the GNU version of the Collaborative International Dictionary of English
adj. not capable of undergoing fission{4}; -- of atoms or chemical elements. Opposite of fissionable.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. not capable of undergoing fission
Word Usage
"Ninety-five percent of a spent fuel rod is plain old U-238, the nonfissionable variety that exists in granite tabletops, stone buildings and the coal burned in coal plants to generate electricity."