Internal Revenue Service

noun

1. the division of the U.S. Department of the Treasury that collects internal revenue, including income taxes and excise taxes, and that enforces revenue laws. IRS

Internal Revenue Service

¹

1. A federal agency, part of the Department of the Treasury, that collects most federal taxes, including income and Social Security taxes.

Internal Revenue Service

²

1. Part of the United States Department of the Treasury. The IRS is responsible for the collection of all federal taxes, except customs duties.