O/S
| Acronym | Definition |
|---|---|
| O/S | Operating System |
| O/S | Outside |
| O/S | One Size |
| O/S | on sale |
| O/S | Offset |
| O/S | Overseas |
| O/S | Outstanding (unpaid insurance claim) |
| O/S | Out of State |
| O/S | Over Stock |
| O/S | Oversize (Canada Post) |
| O/S | On Scene |
| O/S | Outstanding Shares (stock market) |
| O/S | Operational/Support |
| O/S | Outstation |
| O/S | Ocean Surveillance |
| O/S | Outlaw Shark |
| O/S | Organisation/Schmelt (Germany/Poland) |