Bouncer

Someone paid by the owner of a watering hole to reason with the unreasonable.

“Stiffy, though one of those girls who enjoy in equal quantities the gall of an army mule and the calm insouciance of a fish on a slab of ice, had unquestionably gone up in the air a bit when I had seemed about to explain to Stinker my motives for being in the room. I recalled the feverish way in which she had hustled him out, like a small bouncer at a pub ejecting a large customer.”

P. G. Wodehouse, The Code of the Woosters (1938).