| Abbreviation | Definition |
|---|---|
| NSS | Non-Self-Sustaining |
| NSSC | Naval Sea Systems Command (non-standard) |
| NSSDA | National Standard for Spatial Data Accuracy |
| NSSDR | Navy Sea Service Deployment Ribbon (U.S. Military) |
| NSSE | National Special Security Event |
| NSSMS | NATO Sea Sparrow Missile System |
| NSST | Naval Space Support Team |
| NST | National Geospatial-Intelligence Agency Support Team |
| NSTAC | National Security Telecommunications Advisory Committee |
| NSTC | Naval Service Training Command |
| NSTD | Non-System Training Device |
| NSTD | Non-System Training Devices |
| NSTDR | Non-System Training Device Requirement |
| NSTISS | National Security Telecommunications and Information Systems Security |
| NSTISSAM | National Security Telecommunications and Information Systems Security Advisory Memorandum |
| NSTL | National Software Testing Laboratories |
| NSTL | National Strategic Targets List |
| NSTL | Naval Science and Technological Laboratory |
| NSTS | National Secure Telephone System |
| NSTUD | National System Tactical User Device |