| O |
Over (to you) |
| OATUS |
On A Totally Unrelated Subject |
| OAUS |
On An Unrelated Subject |
| OB |
Obligatory (frequently Ob) |
| OBTW |
Oh |
| OD |
OverDose; Oh Dear |
| OFO |
Out F---ing Off |
| OFS |
One Finger Salute |
| OIC |
Oh |
| OMFG |
Oh My F---ing God! |
| OMG |
Oh My God! |
| ONNA |
Oh No |
| ONNTA |
Oh No |
| OO |
Over and Out |
| OOSOOM |
Out Of Sight |
| OOTB |
Out Of The Box |
| OOTC |
Obligatory On Topic Comment |
| OPL |
Obvious Panty Line |
| OPM |
Other People's Money |
| OPP |
Other People's Problems |
| OSIF |
Oh S--- |
| OSIM |
Oh Shoot It's Monday |
| OSU |
Officially Sanctioned User |
| OT |
Off Topic |
| OT1H |
On The One Hand |
| OTBE |
Over Taken By Events (orig. military) |
| OTC |
Over The Counter |
| OTD |
Out The Door |
| OTF |
On The Floor |
| OTFM |
Only The Facts, Mam |
| OTK |
Over The Knee |
| OTL |
Out To Lunch |
| OTOH |
On The Other Hand; On The One Hand |
| OTOOH |
On The Other Other Hand |
| OTT |
Over The Top |
| OTTH |
On The Third Hand |
| OTTOMH |
Off The Top Of My Head |
| OTTOMHAROO |
Off the Top of My Head and Rolling Out of Bounds |
| OTTOMHAROOB |
Off the Top of My Head and Rolling Out of Bounds |
| OTW |
On The Whole |
| OW |
Oh Well |
| OWTTE |
Or Words To That Effect |
