Tarai, also spelled Terai,  region of northern India and southern Nepal running parallel to the lower ranges of the Himalayas. A strip of undulating former marshland, it stretches from the Yamuna River in the west to the Brahmaputra River in the east.

In North Bengal Tarai is Known as Dooars. Western part of the Teesta River is called Tarai. Eastern part of the Teesta to Shankas River is known as Dooars.