Male masturbation. A term most prevalently used by members of the British upper-middle class.

The term 'chap' was used by their parents during their infancy, as the word 'Penis' was considered too vulgar.
"I tell you what Bertie, today's been monstrous. I can't wait to get home tonight so I can get chap in hand."
by Tooting Sigh August 10, 2018
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