The Collaborative International Dictionary of English v.0.48:

Hyperaemia \Hy`per*[ae]"mi*a\, n. [NL., fr. Gr. "ype`r over +
   a"i^ma blood.] (Med.)
   A superabundance or congestion of blood in an organ or part
   of the body.
   [1913 Webster]

   Active hyper[ae]mia, congestion due to increased flow of
      blood to a part.

   Passive hyper[ae]mia, interchange due to obstruction in the
      return of blood from a part. -- Hy`per*[ae]"mic, a.
      [1913 Webster]