revenue enhancement, tax, taxation - charge against a citizen's person or property or activity for the support of government

estimated tax - income tax paid periodically on income that is not subject to withholding taxes; based on the taxpayer's predicted tax liability

FICA - a tax on employees and employers that is used to fund the Social Security system

withholding tax, withholding - income tax withheld from employees' wages and paid directly to the government by the employer

supertax, surtax - an additional tax on certain kinds of income that has already been taxed