E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Sit Upon (To).
To snub, squash, smother, set down; the Latin insides. Charlotte Brontë, in Shirley (xxviii.), uses a phrase which seems analagous: Miss Keeldar says she mentioned the mischance to no oneI preferred to cushion the matter.
Mr. Schwann and his congeners should be most energetically sat upon by colleagues and opponents alike, by everyone, in fact, who has the welfare of the empire at heart.The World, April 6th, 1892, p. 19.