| IRR | insusceptible of reform |
|---|---|
| IRR | a region that is related ethnically or historically to one country but is controlled politically by another |
| IRR | the doctrine that irredenta should be controlled by the country to which they are ethnically or historically related |
| IRR | an advocate of irredentism |
| IRR | incapable of being made smaller or simpler |
| IRR | impossible to deny or disprove |
| IRR | (informal) regardless |
| IRR | merchandise that has imperfections |
| IRR | a member of an irregular armed force that fights a stronger force by sabotage and harassment |
| IRR | not occurring at expected times |
| IRR | independent in behavior or thought |
| IRR | used of independent armed resistance forces |