| Acronym | Definition |
|---|
| IAR | Ignore All Rules (Wikipedia) |
| IAR | International Animal Rescue |
| IAR | Institute for Aerospace Research |
| IAR | Institute of Audio Research (New York, NY) |
| IAR | Investment Advisor Representative |
| IAR | Infantry Automatic Rifle (US Marine Corps) |
| IAR | Institute for Agricultural Research (Nigeria) |
| IAR | Interim Assistance Reimbursement |
| IAR | Instruction Address Register |
| IAR | Initial Assessment Report |
| IAR | Initiative for Architectural Research |
| IAR | Initial Address Reject (ATMF) |
| IAR | Independent Annual Review |
| IAR | Inventory Adjustment Report |
| IAR | In A single Round (gaming) |
| IAR | International Association of Rubberists |
| IAR | Ion Assisted Reaction |
| IAR | Independent Assessment Report |
| IAR | Investment Analysis Report |
| IAR | Independent Applied Research |
| IAR | Irradiation Anneal Reirradiation |
| IAR | Instantaneous-to-Average Power Ratio |
| IAR | Intelligence Area of Responsibility |
| IAR | Internal Anomaly Report |
| IAR | Interoperability Assessment Report |
| IAR | Independent Architecture Review |
| IAR | Inter-Agency Rate |
| IAR | Incident/Accident Report |
| IAR | Integrated Avionics Racks |
| IAR | Imagery Analysis Report |
| IAR | Instruction Access Register |
| IAR | Initial Address Register |
| IAR | Inertial Attitude Reference |
| IAR | I am Revolution (band) |
| IAR | Instruction Approval Release |
| IAR | Immediate Air Request |
| IAR | ISDN Automatic Recall |
| IAR | Illinois Auto Racing |
| IAR | Institute for American Relations |
| IAR | Internal Assessment Review |
| IAR | Inventory Adjustment Rate |
| IAR | Immediate-Phase Asthmatic Reaction |
| IAR | Intra-Area Routing (Cisco) |
| IAR | Informacyjnej Agencji Radiowej (Polish: Radio Information Agency) |