brass monkies 

incredibly cold, freezing in fact.
derived from the saying 'it's cold enough to freeze the bollocks of a brass monkey' it would need to be incredlibly cold to bring brass to a point where it would just become so brittle it broke away

'gawd it's brass monkies out there innit?'

brass monkies by god bless filler bunny September 19, 2005

brass monkie 

A heroin user
(Cockney rhyming slang - junkie)

"They put UV lights in the crapper at asda so the brass monkeys could not find a vein to jack up."

brass monkie by Juan Skinner July 13, 2005