Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
mīrācŭla, ae, f. [miror], a marvellously ugly woman (ante-class.): diobolares, miraculae, Plaut. Fragm. ap. Varr. L. L. 7, § 64 Müll.: miraculae a miris, id est, monstris, Varr. ib.