A rabbet (also known as rebate) is a recess or groove cut into the edge of a piece of machineable material, usually wood. When viewed in cross-section, a rabbet is two-sided and open to the edge or end of the surface into which it is cut.
The spelling rabbet is probably a derivation of rebate, the latter being more common outside of North America.
An example of the use of a rabbet is in a glazing bar where it makes provision for the insertion of the pane of glass and putty. It may also accommodate the edge of the back panel of a cabinet. It is also used in door and casement window jambs.