There are 2 main definitions of Ob in English:

Ob1

Syllabification: Ob
Pronunciation: /äb, ôb
 
/
The principal river of the western Siberian lowlands and one of the largest rivers in Russia. Rising in the Altai Mountains, it flows north and west for 3,481 miles (5,410 km) before entering the Gulf of Ob (or Ob Bay), an inlet of the Kara Sea, a part of the Arctic Ocean.

Definition of Ob in:

There are 2 main definitions of Ob in English:

OB2

Line breaks: OB

Entry from British & World English dictionary

abbreviation

British
Outside broadcast.

Definition of Ob in: