| Abbreviation | Definition |
|---|---|
| SEAP | Spouse Employment Assistance Program |
| SEARAY | Navy Demonstration of Air to Surface Fiber Optic Guidance |
| SEAS | Simultaneous Engagement Armament System |
| SEASTRAT | Strategic Sealift Planning System |
| SEAT | Single Engine Air Tanker |
| SEBA | Synthetic Environment Based Acquisition |
| SEC | Seconds |
| SEC | Section |
| SEC | Security and Exchange Commission |
| SEC | Single Edge Cartridges |
| SEC | Submarine Element Coordinator |
| SECAF | SECretary of the Air Force |
| SECAM | Séquentiel Couleur Avec Mémoire |
| SECARMY | SECretary of the ARMY |
| SECC | Single Edge Contact Cartridge |
| SECDEF | Secretary of Defense |
| SECDHS | Secretary of The Department of Homeland Security |
| SECHS | Secretary of Homeland Security |
| SECIF | Security Interface Software |
| SECM | Shop Equipment - Contact Maintenance |