Source : Webster's Revised Unabridged Dictionary (1913)

Adumbration \Ad`um*bra"tion\, n. [L. adumbratio.]
   1. The act of adumbrating, or shadowing forth.

   2. A faint sketch; an outline; an imperfect portrayal or
      representation of a thing.

            Elegant adumbrations of sacred truth. --Bp. Horsley.

   3. (Her.) The shadow or outlines of a figure.

Source : WordNet®

adumbration
     n 1: the act of providing vague advance indications; representing
          beforehand [syn: {prefiguration}, {foreshadowing}]
     2: a sketchy or imperfect or faint representation