snout
1: An animal's nose.  Also used as an insult for someone with a big nose, or to describe a greedy businessman (eg: snout in the trough).
2: A cigarette (other slang terms for this include fag, cancer stick and coffin nail).
3: A police informant.  The term presumably derives from the informant 'sniffing out villains'.  Other slang terms for a police informant include grass, stool-pigeon and copper's nark.
"Getting snout in jail is a nightmare if you used to be a police snout".
