| Acronym | Definition |
|---|
| IIR➣Infinite Impulse Response (digital filter design and signal processing) |
| IIR➣Institute for International Research |
| IIR➣Institute of Innovation Research (Japan) |
| IIR➣International Institute of Refrigeration (est. 1908) |
| IIR➣Infrared Imaging Radiometer |
| IIR➣Incremental Image Rendering |
| IIR➣Infinite Impulse Response |
| IIR➣Inter Interface Relationships |
| IIR➣Institute for Intergovernmental Research |
| IIR➣Institute of International Relations |
| IIR➣Industry Issue Resolution (pilot program of US Internal Revenue Service and Treasury Department) |
| IIR➣Imaging Infrared |
| IIR➣Installment to Income Ratio (finance) |
| IIR➣Industrial Information Resources |
| IIR➣International Institute of Reflexology |
| IIR➣Intelligence Information Report |
| IIR➣Intelligent Information Retrieval |
| IIR➣If I Recall |
| IIR➣Interactive Information Retrieval |
| IIR➣Indo-Iranian (linguistics) |
| IIR➣Immediate Impulse Response |
| IIR➣Halogenated Butyl Rubber |
| IIR➣Injury Incidence Rate |
| IIR➣Imagery Interpretation Report |
| IIR➣Intermediate-Node Initiated Reservation |
| IIR➣Interlinking Internal Reference |
| IIR➣Inter-Interface Relationships |
| IIR➣Imagery Intelligence Report |
| IIR➣Inertial Instrument Unit |
| IIR➣Initial Imagery Report |
| IIR➣Isstituto Italiano del Rame |
| IIR➣Intermediate Information Requirement |