The act of excluding a specific amount or quantity from a total to determine what is subject to calculation, often used in financial and tax contexts to reduce taxable income or expenses.

A financial mechanism through which certain expenses or allowances are removed from overall income or revenue for the purpose of tax calculation, thereby decreasing the amount of tax owed.

A formal reduction applied to income or earnings, frequently related to expenses such as medical costs or dependent support, that adjusts the final taxable amount.