What is Reduction?

Legal Definition
In Scotch law. An action brought for the purpose of rescinding, annulling or cancelling some bond, contract or other instrument in writing. 1 Forb. Inst, pt. 4, pp. 158, 159. In French law. Abatement. When a parent gives away, whether by gift inter vivos or by legacy, more than bis portion dis-ponible, (q. v.) the donee or legatee is required to submit to have his gift reduced to the legal proportion.
See also
-- Black's Law Dictionary