Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† ăpŏplēxĭa, ae, or -xis, is, f., = ἀποπληξια or ἀπόπληξις, med. t., apoplexy; form apoplexia, Cael. Aur. Acut. 3, 5.
Form apoplexis, Tert. Anim. 53; Firm. Math. 3, 7, n. 8.