A large criminal plan. Usualy organised while spending time in jail for another crime.
"I got this plan for a big dirty after I get outta here"
by zoobtoob December 8, 2006
Something so awesome and cool, yet gross and greasy.
"Dude, that body suit is old and smells funny..." "WHATEVER, ITS THE BIG DIRTY"
by Nazzy Man and EChris December 13, 2009
An enormous and/or monstrous poopie that is taken in the morning after a long days digestion.

To best encourage a successful Big Dirty one must recite "Big Dirty" multiple times. How loud one can say "Big Dirty" is up to the speakers discretion. This repetition can also be used to invite others to perform a successful Big Dirty.

Reciting "Big Dirty" can also be used to set an uncomfortable tone in any crowded restroom, public or private.
Stall 1: "Big Dirty, Big Dirty, Big Dirty"

Stall 2: Inhabitant leaves the restroom due to uncomfortable atmosphere.
by The Big Dirtier November 13, 2010
Common Nickname for Chief Perkins. Sounds far better than biker trash.
Did you see that sweet sweater big dirty was wearing???
by VFA-83LINERATS December 18, 2009
Let's do a Big Dirty before the concert
by --Mick-- November 21, 2005
A type of belligerent persona, often found passed out fully clothed with open food around him, with the t.v on full blast. Notoriously known to be "forever alone" this specimen will continuously attempt to prove himself despite making a mockery of himself hours ago.
Wow! What a big dirty...

Oh man did you see big dirty last night??

He's big.....he's dirty....your girlfriend hates him...he's big dirty Blake!
by Poloro4 March 22, 2011
A girl with a nice face, but a heavy build. May also be considered as girl who is just fat, or a girl who is fat and ugly.
That girls a Big Dirty, or Toms girlfriend's a Big Dirty or BIG DIRTY!
by yourmom647 March 30, 2011