Doab
/ˈdəʊəb/ /ˈduːəb/(also Duab)
noun
Originally and chiefly in South Asia: (the name of) a strip or narrow tract of land between two rivers; specifically (with the) the area between the rivers Ganges and Jumna in northern India.
Origin
Mid 17th century; earliest use found in Thomas Herbert. From Persian doāb, duāb (often in place names) confluence, land between two rivers, used in India of the tongue of land between the Ganges and Jumna, and of similar tracts in the Punjab, etc., lit. ‘two waters’ from dō two + āb water, perhaps after Hindi dvīpa land between waters, island.