rebate

1. A deduction from an amount that is paid; an abatement.
2. The return of part of an amount already paid.
3. The edge of a roll of film, from which no image can be developed.
4. A rectangular groove made to hold two pieces (of wood etc) together; a rabbet.
5. A piece of wood hafted into a long stick, and serving to beat out mortar.
6. An iron tool sharpened something like a chisel, and used for dressing and polishing wood.
7. A kind of hard freestone used in making pavements.

Plural rebates