The Collaborative International Dictionary of English v.0.48:

Imposthumation \Im*post`hu*ma"tion\, n.
   1. The act of forming an abscess; state of being inflamed;
      suppuration.
      [1913 Webster]

   2. An abscess; an imposthume. --Coxe.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Apostemation \A*pos`te*ma"tion\, n. [LL. apostematio: cf. F.
   apost['e]mation.] (Med.)
   The formation of an aposteme; the process of suppuration.
   [Written corruptly imposthumation.] --Wiseman.
   [1913 Webster]