The Collaborative International Dictionary of English v.0.48:

Abscess \Ab"scess\ ([a^]b"s[e^]s), n.; pl. Abscesses
   ([a^]b"s[e^]s*[e^]z). [L. abscessus a going away, gathering
   of humors, abscess, fr. abscessus, p. p. of absedere to go
   away; ab, abs + cedere to go off, retire. See Cede.] (Med.)
   A collection of pus or purulent matter in any tissue or organ
   of the body caused by infection.
   [1913 Webster + AS]

   Cold abscess,
   (a) an abscess of slow formation, unattended with the pain
       and heat characteristic of ordinary abscesses, and
       lasting for years without exhibiting any tendency towards
       healing; a chronic abscess. AS
   (b) an abscess produced by tubercle bacilli, called also
       tuberculous abscess. --AS
       [1913 Webster + AS]

WordNet (r) 3.0 (2006):

abscess
    n 1: symptom consisting of a localized collection of pus
         surrounded by inflamed tissue