| Meaning | Category |
| Scheduling Information Unsolicited | Business->General |
| Seafarers International Union | Business->Professional Organizations |
| Seiko Instruments USA, Inc. | Business->Firms |
| Sensor Interface Unit | Computing->Hardware Governmental->Military |
| Shelf Interface Unit | Academic & Science->Electronics |
| Signal Interface Unit | Governmental->NASA |
| Simulation Interface Unit | Governmental->Military |
| Siuna, Nicaragua | Regional->Airport Codes |
| Southern Illinois University | Academic & Science->Universities |
| Special Investigations Unit | Community->Law Governmental->Police Governmental->US Government |
| Stimulus Isolation Unit | Medical->Physiology |
Click here to submit an acronym.
