| Acronym | Definition |
|---|
| IWSA➣Interscan Web Security Appliance |
| IWSA➣Integrated Waste Services Association |
| IWSA➣International Water Supply Association |
| IWSA➣InterScan Web Security Appliance (Trend Micro Incorporated) |
| IWSA➣International Water Services Association (now International Water Association) |
| IWSA➣Irish Water Safety Association (est. 1945; Galway, Ireland) |
| IWSA➣International Winter Swimming Association |
| IWSA➣In-Warranty Support Agreement (Trane) |
| IWSA➣Independent Washroom Services Association (UK) |