| Acronym | Definition |
|---|
| SIW | Strong Independent Woman |
| SIW | Stoßfänger in Wagenfarbe (German auto company) |
| SIW | System Information for Windows (system properties and settings display) |
| SIW | Socialist International Women (various locations) |
| SIW | Short Instruction Word |
| SIW | System Information for Windows |
| SIW | Shipping Intelligence Weekly (publication; Clarkson) |
| SIW | Simulation Interoperability Workshop |
| SIW | Sinnlos Im Weltraum (German Star Trek spoof) |
| SIW | Self-Inflicted Wounds |
| SIW | Substrate Integrated Waveguide |
| SIW | Service Interworking (ATM, frame relay, etc.) |
| SIW | Strategic Intelligence Wing |
| SIW | Simulation Works, Inc. (Saint Paul, MN) |
| SIW | Sex Industry Worker (adult services) |
| SIW | School of Infantry Weapons (Singapore Armed Forces) |
| SIW | Silent in Waiting (gaming group) |
| SIW | Software Inspections Workshop (STSC) |
| SIW | Senior Information Warfare Applications Course |
| SIW | Sisters of the Incarnate Word and Blessed Sacrament, Cleveland (religious order) |
| SIW | Share Ideas Willingly |