The Collaborative International Dictionary of English v.0.48:

Infarction \In*farc"tion\, n. [See Infarce.]
   1. The act of stuffing or filling; Specifically: (Med.) the
      formation of an infarct; an overloading and obstruction of
      any organ or vessel of the body; constipation.
      [1913 Webster]

   2. An infarct[2]; as, a cardiac infarction.
      [PJC]

WordNet (r) 3.0 (2006):

infarction
    n 1: localized necrosis resulting from obstruction of the blood
         supply [syn: infarct, infarction]