noun: a friend/partner in crime (acebooncoon) that is smuggling illegal paraphernalia with you. this could include, but is not limited to: drugs, weapons, illegal aliens themselves, kids for the priest, prostitutes, etc.
a smuggle buddy can also be your stash of illegal paraphernalia. it is pocket-sized or can fit in a backpack/messenger/purse and of course, for more desperate situations and best concealment, an anal cavity.
delivery boy: hey man, can you be my smuggle buddy for this one delivery? i can't fit a whole pound in my pockets.
SM: yeah, but you owe me- you remember what happened last time...
dealer: you brought the half, right?
-naw man, i had chuck my smuggle buddy over the bridge...so the cops wouldn't find it on me.