rt. 1 splitting of a heavy atomic nucleus, with a release of energy. 2 cell division as a mode of reproduction. v. (cause to) undergo fission. u fissionable adj. [Latin: related to FISSURE]
rt. 1 splitting of a heavy atomic nucleus, with a release of energy. 2 cell division as a mode of reproduction. v. (cause to) undergo fission. u fissionable adj. [Latin: related to FISSURE]