IRS

part of the U.S. Treasury Department which is responsible for the assessment and collection of most Federal taxes

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) Internal Revenue Service
(hypernym) agency, federal agency, government agency, bureau, office, authority
(part-holonym) Department of the Treasury, Treasury Department, Treasury, United States Treasury

IRS, internal revenue service, part of the U.S. Treasury Department which is responsible for the assessment and collection of most Federal taxes

Internal Revenue Service, governmental department which deals with the collection of income taxes and taxes on domestic goods