Definition of "weazel"

[…] set fire to the library, and stifle him in it like a weazel as he is […]

1840, Frances Trollope, chapter III, in The Vicar of Wrexhill‎, London: Richard Bentley, pages 304–5

[H]e disappeared into his house much as a startled weazel makes for its hole.

1888, J[ames] M[atthew] Barrie, “The Old Dominie”, in Auld Licht Idylls, London: Hodder and Stoughton, […], page 138

Now the first time that his small weazel-eyes happened to light on Billy Budd, a certain grim internal merriment set all his ancient wrinkles into antic play.

1924, Herman Melville, chapter 8, in Billy Budd‎, London: Constable & Co.