Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
immundĭtĭa (inm-), ae, f. [immundus], uncleanness, impurity, filth, Plaut. Stich. 5, 5, 6.
Also immundĭtĭes, ēi, Tert. Mon. 7.
In plur., Col. 1, 6, 11; 12, 3, 8; Dig. 43, 23, 1, § 2; Tert. Res. Carn. 47: continet se a viis nostris, quasi ab immunditiis, Lact. 4, 16, 8.