To be extremely upset. A mix of Pissed Off and Frustrated.

A shitty poster...a pisster.

Coined by a Brit who couldn't say poster...

When you are laughing so hard that you wet your pants.

Two or more people who have established a ritual bond by urinating in the same toilet at the same time. There is no male form of the word, and therefore all people who perform this ritual are "Pissters" with each other, regardless of gender.

a combination of pissing some one off and pestering them at the same time.

To make more pissed off.

Sisters that piss is the same toilet bowl before flushing.