When attempting to urinate in the toilet pan, or urinal, the stream of one's piss breaks into two distinct sub-streams. The result of this phenomenon being that meaningful aim is rendered impossible - ultimately causing piss covered feet, yellow stained trousers or damp knees. The name is derived from the triangle formation of the streams - the angle of which, combined with the aimer's height results in a mathematical impossibility for accuracy.
Fuck, I've got an important presentation and pissangulation has caused me to wet my buff coloured strides and suede shoes - I look like an incontinent fool.
Noun: an archaic device common to British railway station restrooms until the 1960's. The Pisswangle consists of wooden rollers turned by a crank operated by the Pisswangler or Pisswangle operator. The male genatalia is passed through the wangle thus squeezing out the last few drops of urine and preventing seepage into the pants.
"Lord Thistlewick hated dribbles of urine in his pants and always tipped the gent's room pisswangler at Victoria station handsomely."