look up any word, like plopping:
 
1.
Refers to the cost of peeing in a train station toilet, for which you will invariably be charged twenty pence to gain entry. Rhymes with "twenty pence piece".
"I was desperate to pee, but my train wasn't due to leave for a while, so I had to fork out for a twenty pence piss!"
by brosephkirk January 10, 2012