Governmental & Military Abbreviations and Acronyms

1. OS
   Office of Security
2. OS
   Optical Sensor
3. OS
   Other Source
4. OS
   Ordinary Seaman
5. OS
   Officer'S Steward
6. OS
   Operating and Support
7. OS
   Operations Squadron
8. OS
   Outside Scope
9. OS
   on-orbit station
10. OS
    Observers School
11. OS
    Other supplementary
12. OS 2
    Operating System/2
13. OS/360
    IBM 360 operating system (1960s)
14. OS2
    Operating System/2
15. OS2
    OPERATIONS SPECIALIST PETTY OFFICER 2ND CLASS
16. OS2
    ORDINARY SEAMAN 2ND CLASS
17. OS2
    OFFICER'S STEWARD 2ND CLASS (NON PETTY OFFICER
18. OS3
    OFFICER'S STEWARD 3RD CLASS (NON PETTY OFFICER)
19. OS3
    OPERATIONS SPECIALIST PETTY OFFICER 3RD CLASS
20. OSA
    Office of The Secretary of The Army

Last updated: May 24, 2020 — Total entries: 74,797