1610s, "deputy governor in Mogul Empire," Anglo-Indian, from Hindi nabab, from Arabic nuwwab, honorific plural of na'ib "viceroy, deputy," from base n-w-b "to take someone's place." Also used of Europeans who came home from India having made a fortune there, hence "very rich man" (1764).
英英释意
1. a governor in India during the Mogual empire
2. a wealthy man (especially one who made his fortune in the Orient)