Internal Revenue Service

governmental department which deals with the collection of income taxes and taxes on domestic goods

The Internal Revenue Service (IRS) is the United States federal government agency that collects taxes and enforces the internal revenue laws. The official U.S. Treasury regulations provide (in part): HistoryBureau of Internal Revenue In 1862, during the Civil War, President Lincoln and Congress created the office of Commissioner of Internal Revenue and enacted an income tax to pay war expenses (see Revenue Act of 1862). The position of Commissioner exists today as the head of the Internal Revenue Service.
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Noun
1. the bureau of the Treasury Department responsible for tax collections
(synonym) IRS
(hypernym) agency, federal agency, government agency, bureau, office, authority
(part-holonym) Department of the Treasury, Treasury Department, Treasury, United States Treasury

The federal agency responsible for the collection federal taxes, including personal and corporate income taxes , social security taxes, and excise and gift taxes.