Noun

chiaus ‎(plural chiauses)

1. (historical) An Ottoman Empire court official; an attendent, messenger, herald, interpreter.
2. (historical) An Ottoman Empire çavuş ‎(“sergeant”).
3. Obsolete spelling of chouse ‎(“a swindler”)
   • 1610, Jonson, Ben, “The alchemist”, in Charles W. Eliot, editor, Elizabethan Drama, The Harvard classics, volume 47, part 2, New York: P. F. Collier & Son, published 1910, OCLC 68745068, page 552:

        Dap.   And will I tell then! By this hand of flesh,
     Would it might never write good courthand more,
     If discover. What do you think of me,
     That I am a chiaus?
        Face.   What’s that?
        Dap.   The Turk was, here―
     As one would say, do you think I am a Turk?
        Face.   I’ll tell the doctor so.
        Dap.   Do, good sweet captain.

Verb

chiaus ‎(third-person singular simple present chiauses, present participle chiausing, simple past and past participle chiaused)

1. Obsolete spelling of chouse ‎(“cheat, trick, swindle”)
   • 1893 November 16, Mynors Bright, Henry Benjamin Wheatley, editors, The diary of Samuel Pepys, for the first time fully transcribed from the shorthand manuscript in the Pepysian library, Magdalene College, Cambridge, volume 5, New York: G. E. Groscup, OCLC 646828332, pages 117–118, note 2:

     The word chouse appears to have been introduced into the language at the beginning of the seventeenth century. In 1609, a Chiaus sent by Sir Robert Shirley, from Constantinople to London, had chiaused (or choused) the Turkish and Persian merchants out of ₤4,000, before the arrival of his employer, and had decamped. The affair was quite recent in 1610, when Jonson's "Alchemist" appeared, in which it is thus alluded to: […]

References

1. ↑ "Chiaus" in A New English dictionary on historical principles, Oxford: Clarendon Press, 1893, volume 2, p. 334.

• “chiaus” in Dictionary.com Unabridged, v1.0.1, Lexico Publishing Group, 2006.
• “chiaus, n.”, in OED Online, Oxford: Oxford University Press, launched 2000.
• chiaus in The Century Dictionary, The Century Co., New York, 1911
• chouse in The Century Dictionary, The Century Co., New York, 1911