Black's Law Dictionary (2nd edition)dictionaries

Offset

A deduction; a counterclaim; a contrary claim or demand by which a given claim may be lessened or canceled. See Leonard v. Charter oak L. Ius. Co., 05 Conn. 529, 33 Atl. 511; Cable Flax Mills v. Early, 72 App. Div. 213, 76 N. Y. Supp. 191. The more usual form of the word is “set-off,” (Or v

Source: Black’s Law Dictionary 2nd Ed (1910)