The Collaborative International Dictionary of English v.0.48:

Blending \Blend"ing\, n.
   1. The act of mingling.
      [1913 Webster]

   2. (Paint.) The method of laying on different tints so that
      they may mingle together while wet, and shade into each
      other insensibly. --Weale.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Blend \Blend\ (bl[e^]nd), v. t. [imp. & p. p. Blended or
   Blent (bl[e^]nt); p. pr. & vb. n. Blending.] [OE.
   blenden, blanden, AS. blandan to blend, mix; akin to Goth.
   blandan to mix, Icel. blanda, Sw. blanda, Dan. blande, OHG.
   blantan to mis; to unknown origin.]
   1. To mix or mingle together; esp. to mingle, combine, or
      associate so that the separate things mixed, or the line
      of demarcation, can not be distinguished. Hence: To
      confuse; to confound.
      [1913 Webster]

            Blending the grand, the beautiful, the gay.
                                                  --Percival.
      [1913 Webster]

   2. To pollute by mixture or association; to spoil or corrupt;
      to blot; to stain. [Obs.] --Spenser.
      [1913 Webster]

   Syn: To commingle; combine; fuse; merge; amalgamate;
        harmonize.
        [1913 Webster]

WordNet (r) 3.0 (2006):

blending
    n 1: the act of blending components together thoroughly [syn:
         blend, blending]
    2: a gradation involving small or imperceptible differences
       between grades [syn: shading, blending]