Definition of "facer"

I made £150 by Alton Locke, and never lost a farthing; and I got, not in spite of, but by the rows, a name and a standing with many a one who would never have heard of me otherwise, and I should have been a stercoraceous mendicant if I had hollowed when I got a facer, while I was winning by the cross, though I didn't mean to fight one.

1856 May, Thomas Hughes, quoting Charles Kingsley, “Prefatory Memoir”, in Charles Kingsley, Alton Locke, Tailor and Poet. […], London: Macmillan and Co., published 1876, page lvi

“You're such a snob,” she said, with a provoking laugh; coming from the family he was thought to be snobbish about, this was a bit of a facer.

2004, Alan Hollinghurst, chapter 1, in The Line of Beauty […], 1st US edition, New York, N.Y.: Bloomsbury Publishing, page 6

He [Joschka Fischer] was for Nato, looser visa rules and—quite the facer for his pacifist colleagues—the bombing of Serbia.

2024 January 27, Janan Ganesh, “Could there be a liberal demagogue?”, in FT Weekend, Life & Arts, page 21