The Collaborative International Dictionary of English v.0.48:

Launder \Laun"der\, v. t. [imp. & p. p. Laundered
   (l[add]n"d[~e]rd or l[aum]n"d[~e]rd); p. pr. & vb. n.
   Laundering.]
   1. To wash, as clothes; to wash, and to smooth with a
      flatiron or mangle; to wash and iron; as, to launder
      shirts.
      [1913 Webster]

   2. To lave; to wet. [Obs.] --Shak.
      [1913 Webster]