| Abbreviation | Definition |
|---|---|
| SECNAV | Secretary of the Navy |
| SECNAVINST | Secretary of The Navy Instruction |
| SECOMP | Secure Communications Package |
| SECOMP | Secure En Route Communications Package |
| SECORD | Secure Cord Switchboard |
| SECRA | Secondary Radar Data Only |
| SECREL | SECret RELeasable |
| SECSTATE | Secretary of State |
| SECT | Section |
| SECTRANS | Secretary of Transportation |
| SED | Signals External Data |
| SED | Software Engineering Design |
| SED | Software Engineering Directorate |
| SEDAS | Spurious Emission Detection Acquisition System |
| SEDRE | Sea Emergency Deployment Readiness Exercise |
| SEDS | Small Expendable Deployer System |
| SEE | Small Emplacement Excavator |
| SEE | Standard External Evaluation |
| SEE | Supplementary Electronic Equipment |
| SEES | Standard Entry/ Exit Service |