The Collaborative International Dictionary of English v.0.48:

Abluent \Ab"lu*ent\, a. [L. abluens, p. pr. of. abluere to wash
   away; ab + luere (lavere, lavare). See Lave.]
   Washing away; carrying off impurities; detergent. -- n.
   (Med.) A detergent. AS
   [1913 Webster]