| O/B | On Board 
| Others |
| O/B | OnBoard
| Others |
| O/B | Operational Base
| Others |
| O/B | Outboard
| Others |
| o/b | overboard
| Others |
| OB | OB abbreviation
| Others |
| OB | OBdormio (died)
| Others |
| OB | Obese
| Others |
| OB | Obese Beast
| Others |
| OB | Obesity Br
| Others |
| OB | Object Bus
| Others |
| OB | Obnoxious Because
| Others |
| OB | Obnoxious Blowhard
| Others |
| OB | Obstetrician
| Others |
| OB | Obstetrician Or Baby
| Others |
| OB | OBstetrics
| Others |
| OB | Obviously Boilerroom
| Others |
| OB | Occlusion Bodies
| Others |
| OB | Occult Blood
| Others |
| OB | Occurrence Book
| Others |
| OB | Ocean Bay
| Others |
| OB | Ocean Beach
| Others |
| OB | Odd Ball
| Others |
| OB | Odie's Baby
| Others |
| OB | Odious Brick
| Others |
| OB | Off Break
| Others |
| OB | Off Broadway
| Others |
| OB | Offensive Bonus
| Others |
| OB | Office Building
| Others |
| OB | Office of Biostatistics
| Others |
| OB | Official Business
| Others |
| OB | Oh Brian
| Others |
| OB | Ohne Befund
| Others |
| OB | Ohne Binde
| Others |
| OB | Ol B
| Others |
| OB | Old Bezel
| Others |
| OB | Old Boy
| Others |
| OB | Old Boys
| Others |
| OB | Old Bridge
| Others |
| OB | Old Buddy
| Others |
| OB | Old Burroughs
| Others |
| OB | Old Butterpaws
| Others |
| OB | Olies Blog
| Others |
| OB | Oligosaccharide Binding
| Others |
| OB | Olympic Boycott
| Others |
| OB | Olympic Building
| Others |
| OB | On Baseballs
| Others |
| OB | One Billion
| Others |
| OB | Only Bass
| Others |
| OB | Open Beta
| Others |
| OB | Open Bottle
| Others |
| OB | Open Box
| Others |
| OB | Open Branched
| Others |
| OB | Opening Balance
| Others |
| OB | Operating Base
| Others |
| OB | Operating Budget
| Others |
| OB | Operation Blackboard
| Others |
| OB | Operation Blessing
| Others |
| OB | Operation Brotherhood
| Others |
| OB | Optical Bar
| Others |
| OB | Optical Bench
| Others |
| OB | Option Button
| Others |
| OB | Optional Brakes
| Others |
| OB | Or better
| Others |
| OB | Orange and Blue
| Others |
| OB | Orange Blotch
| Others |
| OB | Orange Blotched
| Others |
| OB | Orange Book (Approved Drug Products with Therapeutic Equivalence Evaluations)
| Others |
| OB | Orange Boy
| Others |
| OB | Orchard Breezin
| Others |
| OB | Orchard Breezinamp
| Others |
| OB | Order of Battle
| Others |
| OB | Order of Biologists
| Others |
| OB | Ordinary Builders
| Others |
| OB | Ordinary Building
| Others |
| OB | Organisational Behaviour
| Others |
| OB | Organization Behavior
| Others |
| OB | Organizational Behavior
| Others |
| OB | Organizational Behaviur
| Others |
| OB | Organizational Business
| Others |
| OB | Organized Baseball
| Others |
| OB | Oriental Beer
| Others |
| OB | Oriental Brewing
| Others |
| OB | Original Blogger
| Others |
| OB | Original Box
| Others |
| OB | Original Broadcast
| Others |
| OB | Original Budget
| Others |
| OB | Orlando Bloom
| Others |
| OB | Oscar Bravo
| Others |
| OB | Ossewa Brandwag
| Others |
| OB | Ostby Barton
| Others |
| OB | Other Board
| Others |
| OB | Out Board
| Others |
| OB | Out Of Bounds
| Others |
| OB | Out of Business
| Others |
| OB | Outdoor Broadcast
| Others |
| OB | Outdoors About
| Others |
| OB | Outer Banks
| Others |
| OB | Output Block
| Others |
| OB | Output Buffer
| Others |
| OB | Output Buffering
| Others |
| OB | Outside Billing
| Others |
| OB | Outside Broadcast
| Others |
| OB | Outstanding Balance
| Others |
| OB | Outta Business
| Others |
| OB | Outward Bound
| Others |
| OB | Over Boost
| Others |
| OB | Over Burden
| Others |
| OB | Overflow Bucket
| Others |
| OB | Overseas Built
| Others |
| OB | Oversized Box
| Others |
| OB | Owl Bait
| Others |
| ob. | died (obit [Lat.])
| Others |
| Ob. | Oboe
| Others |