UK ~ is the vestle of a single person for the purpose of wanking / masturbation / pulling one off. Although commonly male vestle, it is now common among female students too.
When you fail at something in life (eg. failing an exam or not getting a job), go home and spend an hour just standing in the shower, propping yourself up against the wall with your eyes on your feet.
Caleb knew the only thing to do after he didnt get prefect was take a failure shower.