Looking for online definition of OB or what OB stands for? OB is listed in the World’s largest and most authoritative dictionary database of abbreviations and acronyms.An OB GYN is a physician who specializes in medical and surgical care to women with expertise in pregnancy, childbirth, and disorders of the reproductive system..River in W Siberia, flowing from the Altai Mountains northwest north into the Gulf of Ob , mi , km arm of the Kara Sea, in NW Siberia c. mi km long .English  Etymology . From Latin ob Prefix . ob non productive Against facing a combining prefix found in verbs of Latin origin. Of a reversed shape .Ob definition, a river in the W Russian Federation in Asia, flowing NW to the Gulf of Ob. miles km long. See more..Odrt bensin bur upp bi OB lykilinn og OB frelsi.
Rows Acronym Definition OB Obstetrics OB Out of the Blue OB Outside Broadcast OB Outboard OB Out of Bounds National Park Service or golf slang OB Outward Bound OB Orlando Bloom .Ob pref. Inverse inversely obcordate. [New Latin, short for obvers, obversely, from Latin obversus, past participle of obvertere, to turn toward ob , toward, against .River in W Siberia, flowing from the Altai Mountains northwest north into the Gulf of Ob , mi , km arm of the Kara Sea, in NW Siberia c. mi km long .