a phrase uttered in response to a thing or situation that is generally unwanted or considered bad. the origins are unknown, but it is believed to come from the Tim Burton film "Sweeney Todd". Can also be used in replace of gay, or sucks (ie: "it's piss because...") The 'it' in "it's piss because..." serves the purpose as a generic noun, as in "it sucks" or "it's gay".
you: so, are you done with midterms?
me: no, I have all of 'em this week, and I haven't studied at all. THIS IS PISS!!!
you: this IS piss.