Slang term for alcohol. Usually of a strong nature, and generally in abundance. People who break out the firejuice definitely intend to get utterly shit-faced. No kiddie drinks... a la Bacardi Breezer.
"Well, that's the last exam."
"Do you think we passed?"
"I don't know, but I plan on getting severely pissed until we find out."
"Well said. Break out the firejuice, mate."