a member of the princely and military castes of the former Hindu kingdom of Maharashtra in central India. The Marathas rebelled against the Moguls and in 1674 established their own kingdom. They came to dominate southern and central India but were later subdued by the British.
via Hindi from Sanskrit Mahārāṣṭra 'great kingdom'
Maratha in other Oxford dictionaries
Definition of Maratha in the US English dictionary