The Collaborative International Dictionary of English v.0.48:

Decantation \De`can*ta"tion\ (?; 277), n. [Cf. F.
   d['e]cantation.]
   The act of pouring off a clear liquor gently from its lees or
   sediment, or from one vessel into another.
   [1913 Webster]

WordNet (r) 3.0 (2006):

decantation
    n 1: the act of gently pouring off a clear liquor (as from its
         original bottle) without disturbing the lees