From Longman Dictionary of Contemporary EnglishInternal Revenue ServiceInˌternal ˈRevenue ˌService (also Internal Revenue) PET (abbreviation the IRS) the government organization in the US which is responsible for collecting national taxes.
Examples from the Corpus
Internal Revenue Service• The Internal Revenue Service acknowledges that McGill, a retired civil engineer, never owed the government.• If not, the Internal Revenue Service certainly hammered home the message.• The retired Internal Revenue Service employee paid $ 15,500 for the two-bedroom mobile home on space 72.• The Internal Revenue Service has been battling him for years for back taxes and penalties related to one venture.• An Internal Revenue Service probe might follow.• The Internal Revenue Service thought it had a smoking gun.From Longman Business DictionaryInternal Revenue ServiceInˌternal ˈRevenue ˌService abbreviation IRS nounTAXORGANIZATIONS the government department that collects national taxes in the USHe was convicted of cheating the Internal Revenue Service of $1.7 million. → see also Inland Revenue