INTERNAL REVENUE SERVICE(noun)Did you mean?RhymesDefinitions There is 1 meaning of the phrase Internal Revenue Service. Internal Revenue Service - as a noun The bureau of the treasury department responsible for tax collections Synonyms (Exact Relations)irsWord Variations & RelationsStarts IStarts INStarts INTStarts INTEEnds EEnds CEEnds ICEEnds VICEStarts I & ends EStarts IN & ends EStarts I & ends CEA-Z Proximitiesintermured13intermures12intermuring14intern6internal8 Internal Revenue Service internalisation15internalise11internalised13internalises12internalising14