fis·sile 
(fĭsəl, -īl′)
(fĭsəl, -īl′)adj.
1. Possible to split.
2. Physics Fissionable, especially by neutrons of all energies.
3. Geology Easily split along close parallel planes.
[Latin fissilis, from fissus, split; see FISSI-.]
fis·sili·ty (fĭ-sĭlĭ-tē) n.