| Acronym | Definition |
|---|
| SIAD | Supersonic Inflatable Aerodynamic Decelerator (US NASA) |
| SIAD | Sierra Army Depot |
| SIAD | Short Interval Additional Dose (medication) |
| SIAD | Serial Interface Adapter Device |
| SIAD | Self Injury Awareness Day |
| SIAD | Statistical Information Analysis Division |
| SIAD | Sustainable Integrated Area Development |
| SIAD | Système Informatique d'Aide à la Décision (French: decision support system) |
| SIAD | Societa Italiana Acetilene e Derivati (Italian: Italian Company of Acetylene and Derivatives; Bergamo, Italy) |
| SIAD | Syndrome of Inappropriate Antidiuretic Hormone Secretion |
| SIAD | Système d'Information et d'Aide au Détachement (French: System Information and Support Secondment) |
| SIAD | Synergistic Isogenous Active Decontamination (Synergena) |
| SIAD | Smart Integrated Access Device |
| SIAD | Sisteme de Asistare a Deciziei (Romania) |
| SIAD | Society of Illustrators, Artists & Designers |