social security benefit
(3) Workmen’s compensation benefits substituted for social security benefits For purposes of this section, if, by reason of section 224 of the Social Security Act (or by reason of section 3(a)(1) of the Railroad Retirement Act of 1974), any social security benefit is reduced by reason of the receipt of a benefit under a workmen’s compensation act, the term “social security benefit” includes that portion of such benefit received under the workmen’s compensation act which equals such reduction.