Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
mŭtĭlātĭo, ōnis, f. [mutilo], a maiming, mutilating, mutilation (late Lat.), Cassiod. Var. 10, 28; cf. mutilatio, ἀκρωτηρίασις, Gloss. Philox.