| Abbreviation | Definition |
|---|---|
| SCVI | South Carolina Volunteer Infantry |
| SCW | Seabee Combat Warfare |
| SCW | Spanish Civil War |
| SD | SicherheitsDienst |
| SD | Solicitation Document |
| SD | Special Duty |
| SD | Standby Distribution |
| SD | Strategy Division |
| SD | Structured Design |
| SD | Super-Dreadnought |
| SD | Synchronization Directorate |
| SD/D | System Development and Demonstration life cycle phase |
| SDA | Seventh-Day Adventist |
| SDA | Source Data Automation |
| SDA | Standard Double Arm |
| SDA | System Device Adaptor |
| S-Day | Day The President Authorizes Selective Reserve Call-Up |
| SDB | Satellite Communications Database |
| SDB | SCSI (Small Computer Systems Interface) Disk B |
| SDB | Small and Disadvantaged Businesses |