derogatory term that is factual, and is therefore not a derogatory term. As a result, it makes the user seem useless.
Bob: Don't be such a wanker.
Ben (in response): Don't be such a piss kidney.
Bob: What? What kind of insult is that. You idiot.

(The phrase originates from the television show Peep Show, series four).
by Sir Rory of Prestonia October 19, 2007
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Derogatory insult, used in Peep Show by Mark when he couldn't think of anything more appropriately enraging to call a driver when trying to get run over to avoid his wedding to Sophie.
"You're a piss-kidney."
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