DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   Ob
       n 1: a major river of western Siberia; flows generally northward
            and westward to the Gulf of Ob and the Kara Sea [syn: Ob,
            Ob River]
       2: the branch of medicine dealing with childbirth and care of
          the mother [syn: obstetrics, OB, tocology, midwifery]