deduct

Deduct is a verb with several related meanings centered on subtraction or derivation. In mathematics, accounting, and everyday arithmetic, it means to subtract or take away a part from a total. For example, a tax deduction reduces taxable income; deductions are subtracted from gross pay or gross costs.

Etymology traces deduct to Latin deducere, from de- “away” or “down” and ducere “to lead.” In logic, the process of obtaining a conclusion from premises is called deduction, and the corresponding verb is usually deduce rather than deduct. In general writing, deduct is most common in numerical or financial contexts; using it to mean derive a conclusion is less standard in formal logic.

In finance and payroll, deductions are amounts withheld from pay for taxes, social security, benefits, or retirement contributions. These reductions decrease net pay and can be standard (set by law or policy) or itemized (specific expenses). In budgeting and accounting, to deduct expenses from income is to remove those costs from the total to determine remaining funds or taxable income.

Deduct can also appear in phrases describing the act of reducing an amount or value, such as deducting from a balance or from a price. While the term intersects with several related concepts—such as deduction, deduction in taxes, and pre-tax deductions—its precise use depends on the context, with numerical subtraction being the most common everyday usage.