Definition of "bouncer"

At 199 centimetres and a hundred kilos going up, he was scary big and he found work as a bouncer and enforcer[.]

2010, Peter Corris, Torn Apart, Allen and Unwin, page 117

The stone must be a bouncer.

1842, Thomas De Quincey, “Modern Greece”, in Blackwood's Magazine

"… when he wants to accomplish his purpose, he does not hesitate to invent—I am not quite sure of the word, but I think it is “bouncers.”

1877, W. S. Gilbert, “Engaged”, in Original Plays, Second Series, London: Chatto & Windus, published 1899, page 83

"Why, I'll tell you, Mr. Simple; he's a good tempered, kind fellow enough, but—" / "But what?" / "Such a bouncer!!" / "How do you mean? He's not a very stout man." / "Bless you, Mr. Simple, why don't you understand English. I mean that he's the greatest liar that ever walked a deck. […]"

1833, [Frederick Marryat], chapter XII, in Peter Simple. […], volume II, London: Saunders and Otley, […], published 1834, page 190

He shook his head and took up the child—Dilly kicked out her feet in tiny electric jolts to the full stretch of the Babygro. […] He put the child in the bouncer again.

2019, Kevin Barry, Night Boat to Tangier, New York: Doubleday, pages 82–83