Pissed: either angry or drunk. Sometimes both.
Piss easy: extremely easy.
Pissed off: either in the context of being angry, or having left a place.
Piss Up: an event containing alcohol.
Pissing down: Raining heavily.
Pissed on: usually used to describe being rained on.
Piss around: dawdle or delay; procrastinate.
Pissing contest: attempting to prove one’s abilities are better than someone else’s, for no discernible gain.
Piss faced (see also ‘shitfaced’): inebriated.
Pissy: either angry, or something very small.
Piss-poor/piss-weak: weak or disappointing.
Piss head: Alcoholic individual.
As an example: George and some other piss head got into a pissing contest, where George put in a piss poor effort and got pissed off because it started pissing down. He’d figured it would be piss easy to win, so he was pissy and spent the rest of the afternoon pissing around before deciding to piss off and avoid getting pissed on any further by the rain.