INTERNAL REVENUE SERVICE

Internal Revenue Service. 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. — Abbr. IRS. [Cases: Internal Revenue 3003, 4440–4443. C.J.S. Internal Revenue §§ 4, 607–611, 616, 618.]