Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ŏpīmĭtas, ātis, f. [opimus], plentifulness, abundance, prosperity (ante- and postclass.): opimitates maximae, Plaut. Capt. 4, 1, 2; id. As. 2, 2, 16: praedarum, Amm. 19, 11.