The Collaborative International Dictionary of English v.0.48:

Purulence \Pu"ru*lence\, Purulency \Pu"ru*len*cy\, n. [L.
   purulentia: cf. F. purulence.] (Med.)
   The quality or state of being purulent; the generation of
   pus; also, the pus itself. --Arbuthnot.
   [1913 Webster]

WordNet (r) 3.0 (2006):

purulency
    n 1: symptom of being purulent (containing or forming pus) [syn:
         purulence, purulency]