The Collaborative International Dictionary of English v.0.48:

Effluent \Ef"flu*ent\, a. [L. effluens, -entis, p. pr. of
   effluere to flow out; ex + fluere to flow: cf. F. effluent.
   See Fluent.]
   Flowing out; as, effluent beams. --Parnell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Effluent \Ef"flu*ent\, n. (Geog.)
   A stream that flows out of another stream or lake.
   [1913 Webster]

WordNet (r) 3.0 (2006):

effluent
    adj 1: that is flowing outward [syn: effluent, outflowing]
    n 1: water mixed with waste matter [syn: effluent,
         wastewater, sewer water]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "effluent":
   affluent, bayou, billabong, branch, confluent, confluent stream,
   dejecta, dejection, dejecture, dendritic drainage pattern,
   discharge, effused, effusive, egesta, ejecta, ejectamenta,
   ejection, excrement, excreta, excretes, extravasate, extravasated,
   extravasation, exudate, exudation, feeder, fork, outbound,
   outflowing, outgoing, outpouring, outward-bound, prong, transudate,
   transudation, tributary, waste, waste matter