Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
mūtŭātĭo, ōnis, f. [mutuor], a borrowing (class.), Cic. Tusc. 1, 42, 100: cum multos minutis mutuationibus defraudāsset, id. Fl. 20, 47: translationes quasi mutuationes sunt, id. de Or. 3, 38, 156.