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1 definition by mr 9"

a mash-up is slang for a get together of similarly minded people so that they might partake in the consumption of drugs and/or alcohol. people on a mash-up get mashed.
mash-ups usually take place at night, but usually go on well in to the morning of the following day (they tend to wind down when the alcohol/drugs run out). unlike a cotch, mash-ups can take place anywhere, in or outside.
H: YOOOOO MAAAAAAAAAAAAAAAAN, on for a phat mash-up tonight?

M: YEAAAAAAAH BLID, let me ring fattypants whitworth and the filthy pikey, see what they's sayin'

H: bring some shroooms blud

M: wouldn't be a mash-up without them
by mr 9" September 03, 2007