also baboo, 1782, Anglo-Indian, "native clerk (originally in Bengal) who writes English," from Hindi babu, title of respect, perhaps originally "father."
In Bengal and elsewhere, among Anglo-Indians, it is often used with a slight savour of disparagement, as characterizing a superficially cultivated, but too often effeminate, Bengali. [Yule and Burnell, "Hobson-Jobson," 1886]
In reference to "the ornate and somewhat unidiomatic English of an Indian who has learnt the language principally from books" [OED] from 1878.