The Collaborative International Dictionary of English v.0.48:

Pus \Pus\, n. [L., akin to Gr. ?, ?, and to E. foul: cf. F. pus.
   See Foul, a.] (Med.)
   The yellowish white opaque creamy matter produced by the
   process of suppuration. It consists of innumerable white
   nucleated cells floating in a clear liquid.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Pus
    n 1: the tenth month of the Hindu calendar [syn: Pus, Pansa]
    2: a fluid product of inflammation [syn: pus, purulence,
       suppuration, ichor, sanies, festering]

Moby Thesaurus II by Grady Ward, 1.0:

53 Moby Thesaurus words for "pus":
   carrion, chyle, colostrum, corruption, dandruff, decay, discharge,
   excrement, festering, filth, foul matter, furfur, gangrene, gleet,
   humor, ichor, lachryma, lactation, leukorrhea, lymph, matter,
   mattering, mess, milk, muck, mucor, mucus, obscenity, ordure,
   peccant humor, phlegm, purulence, putrid matter, rankling, rheum,
   rot, running, saliva, sanies, scurf, scuz, serous fluid, serum,
   slime, smut, snot, sordes, suppuration, sweat, tear, teardrop,
   the whites, urine