Dependent—A person, such as a child or parent, for whom a taxpayer may be able to claim a personal exemption if the taxpayer provides more than half of the person's support during the taxable year.
Form W-4, Employee's Withholding Allowance Certificate—A form indicating the number of personal exemptions an employee is claiming and that is used by the employer in determining the amount of income to be withheld from the employee's paycheck for federal-income tax purposes.
Income Taxes—A tax on an individual's or entity's net income.
Internal Revenue Service (IRS) —A unit in the U.S. Department of the Treasury responsible for enforcing and administering the internal-revenue laws and other tax laws except those relating to alcohol, tobacco, firearms, and explosives.
Sales Tax—A tax imposed on the sale of goods and services, usually measured as a percentage of their price.
Tax Deduction—An amount subtracted from gross income when calculating adjusted gross income, or from adjusted gross income when calculating taxable income.
† All definitions come from Black’s Law Dictionary