The Collaborative International Dictionary of English v.0.48:

Attribution \At`tri*bu"tion\, n. [L. attributio: cf. F.
   attribution.]
   1. The act of attributing or ascribing, as a quality,
      character, or function, to a thing or person, an effect to
      a cause.
      [1913 Webster]

   2. That which is ascribed or attributed.
      [1913 Webster]

WordNet (r) 3.0 (2006):

attribution
    n 1: assigning some quality or character to a person or thing;
         "the attribution of language to birds"; "the ascription to
         me of honors I had not earned" [syn: attribution,
         ascription]
    2: assigning to a cause or source; "the attribution of lighting
       to an expression of God's wrath"; "he questioned the
       attribution of the painting to Picasso" [syn: attribution,
       ascription]