Source : Webster's Revised Unabridged Dictionary (1913)

Rebate \Re*bate"\, v. i.
   To abate; to withdraw. [Obs.] --Foxe.

Rebate \Re*bate"\, n.
   1. Diminution.

   2. (Com.) Deduction; abatement; as, a rebate of interest for
      immediate payment; a rebate of importation duties.
      --Bouvier.

Rebate \Re*bate"\, n. [See {Rabbet}.]
   1. (Arch.) A restangular longitudinal recess or groove, cut
      in the corner or edge of any body; a rabbet. See {Rabbet}.

   2. A piece of wood hafted into a long stick, and serving to
      beat out mortar. --Elmes.

   3. An iron tool sharpened something like a chisel, and used
      for dressing and polishing wood. --Elmes.

   4. [Perhaps a different word.] A kind of hard freestone used
      in making pavements. [R.] --Elmes.

Rebate \Re*bate"\, v. t.
   To cut a rebate in. See {Rabbet}, v.

Rebate \Re*bate"\, v. t. [F. rebattre to beat again; pref re-
   re- + battre to beat, L. batuere to beat, strike. See
   {Abate}.]
   1. To beat to obtuseness; to deprive of keenness; to blunt;
      to turn back the point of, as a lance used for exercise.

            But doth rebate and blunt his natural edge. --Shak.

   2. To deduct from; to make a discount from, as interest due,
      or customs duties. --Blount.

Source : WordNet®

rebate
     n 1: a refund of some fraction of the amount paid [syn: {discount}]
     2: a rectangular groove made to hold two pieces together [syn:
        {rabbet}]
     v 1: give a reduction in the price during a sale; "The store is
          rebating refrigerators this week"
     2: cut a rebate in (timber or stone)
     3: join with a rebate; "rebate the pieces of timber and stone"