Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prŏpĕrantĭa, ae, f. [propero], a hastening, haste (very rare; not in Cic. or Cæs.): ex tantā properantiā, Sall. J. 36, 3: periculum ex properantiā, Tac. A. 12, 20.