Definition of "étui"

From the inn she is taken to the house of the procuress, divested of her home-spun garb, and dressed in the gayest style of the day; her pincushion and scissars discarded for an etwee and watch, and the tender native hue of her complexion incrusted with paint, and disguised by patches.

1791 June 1, John Ireland, “The Harlot’s Progress. Plate I.”, in Hogarth Illustrated, volume I, [London]: J[ohn] & J[osiah] Boydell […], pages 4–5

Secondly, glass bottles are useless: the drugs should be stowed away in tin or wooden boxes, such as the natives of the country use, and when a phial is required, it must be fitted into an étui of some kind.

1855, Sir Richard Burton, Personal Narrative of a Pilgrimage to Al-Madinah & Meccah, Dover, published 1964, p. 26 n

And what about that comb in a real-leather etui, what about, what about it – oh, it would get fouled up in no time and it would take an hour of work to remove the grime from between its tight teeth [...].

1972, Vladimir Nabokov, Transparent Things, McGraw-Hill, published 1972, page 13

And from a buff leather etui monogrammed in silver, he extracted one of his Maria Mancinis-- a lovely specimen from the top of the box, flattened on just one side the way he especially liked it [...].

1995, Thomas Mann, translated from the 1925 German by John E. Woods, "The Magic Mountain", Alfred A. Knopf, 1995, p. 46