Green’s Dictionary of Slang

qui-hi n.

also qui-hai, qui-hy
[Urdu koi hai, is anyone there?, the usual summons to a servant; note E.F. Benson’s character, the ex-Indian Army Major Flint, in the Lucia stories, whose catchphrase this is]

(Anglo-Ind.) an English resident of Calcutta; cite 1855 suggests any former Anglo-Indian, not specifically living in Calcutta.

[[Ind]T. Williamson East India Vade-Mecum II 38: All servants come upon being called only; there being no bells hung in any part of the country, and very, very few even of hand-bells to be seen. The common call, Qui hi! (meaning ‘who is there?’) often rouzes a dozen of the slumbering crew, though it is occasionally repeated, with some vociferation too, before one will stir].
[UK]W. Coombe [title] The Grand Master or Adventures of Qui Hi? in Hindostan. A Hudibras Poem in Eight Cantos by Quiz.
[UK]T.E. Hook Sayings and Doings 2nd Ser. 3: Then the rupees of a ‘qui hi,’ [...] And this ‘qui hi’ such speeches made.
[C. D’Oyly] Tom Raw, the Griffin 21: ‘Qui hi?’ anglice, ‘Who’s there?’ It has become a bantering designation of residents of Bengal.
[Ind]G.W. Johnson Stranger in India I 122: I once heard an old Qui Hye declare, ‘that it was true he had destroyed his liver in Calcutta, but then he had eaten Tupsy-mutchees!’.
[UK]New Sporting Mag. (London) Dec. 394: ‘Qui hye’ An animal of the genus homo, peculiar to Bengal, whose principal food consists of curry and pale ale, and whose principal characteristic is a thorough contempt for ‘Ducks’ and ‘Mulls’ .
[UK]N&Q Ser. 1 V 165: Residents of Bengal, Bombay, and Madras are, in Eastern parlance, designated ‘Qui Hies,’ ‘Ducks,’ and ‘Mulls.’.
[UK]Thackeray Newcomes II 229: The old boys, the old generals, the old colonels, the old qui-his from the club, came and paid her their homage.
[Ind]G. Drago John Hobbs 3: ‘Qui hi, or ditcher;’ a ‘benighted Mull’, or an ‘ambitious Duck’. These are nick terms applied to the English residents at the three presidencies – Bengal, Madras, and Bombay respectively. [...] The Bengalee is also called a ‘Ditcher’ from the circumstance of the Mahrattah Ditch encircling Calcutta.
[UK]Hotten Sl. Dict.
[Ind]A. Allardyce ‘The Anglo-Indian Tongue’ in Blackwood’s Edinburgh Mag. May 544/1: The Anglo-Indian household suggests many curious expressions. Bells have never been an institution in India, and the lordly Sahib summons his domestics by a loud shout of ‘Qui hye?’‘Who’s there? who waits?’ From this the Englishman in Bengal derives the familiar sobriquet by which he is distinguished from the ‘Mulls’ of benighted Madras and the ‘Ducks’ of the Bombay Presidency.
[Ind]Yule & Burnell Hobson Jobson 568/1: Bengalis are called ‘Quai Hai’s’ (Who’s there?) from their custom of calling out ‘Quai Hai’ when they want a servant.
[Ind]D. Dewar Bombay Ducks v: [T]he European residents of the Western Presidency were known as Bombay Ducks to distinguish them from Bengal Qui-his and Madras Mulls.