Is it ensure, insure, or assure?
"consisting of broken pieces," 1875, in geology, from Latinized form of Greek klastos "broken in pieces," from klan, klaein "to break," from PIE *kla-, variant of root *kel- "to strike."
clastic clas·tic (klās'tĭk)
Breaking up into pieces or exhibiting a tendency to break or divide.
Separable into parts or having removable sections, as an anatomical model.