"the player on the fielding side who stands behind the wicket or stumps being watchful of the batsman and be ready to take a catch, stump the batsman out and run out a batsman when occasion arises. The wicket-keeper is the only member of the fielding side permitted to wear gloves and external leg guards.
[...]
The keeper's major function is to stop deliveries that pass the batsman (in order to prevent runs being scored as 'byes'), but he can also attempt to dismiss the batsman in various ways: "
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Darling: Erm, not all that good, Blackadder - rather hoped I'd get through the whole show; go back to work at Pratt & Sons; keep wicket for the Croydon gentlemen; marry Doris. Made a note in my diary on my way here; simply says, "bugger."
BBC. Blackadder, season 4: Goodbyeee
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it demanded from him a constant attention, and a quickness of eye and hand, very like that exacted by wicket-keeping.