NASA
| Abbreviation | Meaning | Tamil Meaning | Category |
|---|---|---|---|
| OAP | Over-Anxious Patient | - | NASA |
| OBE | Open Both Ends (known In UK As DNV - Diarrhoea And Vomiting) | - | NASA |
| OBS | Obvious Bullsh*t | - | NASA |
| OFIG | One Foot In The Grave | - | NASA |
| OFIGATOOS | One Foot In The Grave And The Other One Slipping | - | NASA |
| OMGWTFBBQ | Oh My God, What The F*ck, Bar-be-que; A Person Mangled In A Car Crash | - | NASA |
| OPD | Obnoxious Personality Disorder | - | NASA |
| OTD&DDR | Out The Door And Down The Road. | - | NASA |
| OTDPDS | Out The Door Pretty Damn Soon | - | NASA |
| OTLP | On The Launch Pad (to Be Discharged To Home) | - | NASA |