Source : Webster's Revised Unabridged Dictionary (1913)

Imposition \Im`po*si"tion\, n. [F., fr. L. impositio the
   application of a name to a thing. See {Impone}.]
   1. The act of imposing, laying on, affixing, enjoining,
      inflicting, obtruding, and the like. ``From imposition of
      strict laws.'' --Milton.

            Made more solemn by the imposition of hands.
                                                  --Hammond.

   2. That which is imposed, levied, or enjoined; charge;
      burden; injunction; tax.

   3. (Eng. Univ.) An extra exercise enjoined on students as a
      punishment. --T. Warton.

   4. An excessive, arbitrary, or unlawful exaction; hence, a
      trick or deception put on laid on others; cheating; fraud;
      delusion; imposture.

            Reputation is an idle and most false imposition.
                                                  --Shak.

   5. (Eccl.) The act of laying on the hands as a religious
      ceremoy, in ordination, confirmation, etc.

   6. (Print.) The act or process of imosing pages or columns of
      type. See {Impose}, v. t., 4.

   Syn: Deceit; fraud; imposture. See {Deception}.

Source : WordNet®

imposition
     n 1: the act of imposing something (as a tax or an embargo) [syn:
           {infliction}]
     2: an uncalled-for burden; "he listened but resented the
        imposition"