a. [ See Metamorphosis. ] 1. Subject to change; changeable; variable. [ 1913 Webster ]
2. Causing a change of structure. [ 1913 Webster ]
3. (Geol.) Pertaining to, produced by, or exhibiting, certain changes which minerals or rocks may have undergone since their original deposition; -- especially applied to the recrystallization which sedimentary rocks have undergone through the influence of heat and pressure, after which they are called metamorphic rocks. [ 1913 Webster ]