In a game of beer pong a formation in which a single cup is in the back row, two cups in the second row and one cup in front. Sometimes this formation is incorrectly referred to as a "diamond". Prhombus is an abbreviated version of the phrase.
Yo thundercunt . . . re-rack to a power rhombus.
It's not a diamond you stupid asshole. That's a power rhombus. Don't be a douchebag.