In British English slang, particularly of north-west England this means 'lucky' or more accurately 'flukey'. It is usually applied to someone else who has just had a particular piece of outrageous or undeserved luck.
It is typically used with this meaning by young men and schoolboys throughout the north-west of England, not just Liverpool and
Merseyside, but also
Cheshire, etc. However, the usage can occur in other regions of England as well. It has been used to have this meaning throughout most of the period since at least the end of
World War Two.
1. "Rooney fluffed the kick and then the ball ricocheted off the back of
the defender's head into the net! The
jammy bastard!"
2. Dave: "Hey, Gaz, you was late to class for the third time in a row, innit, how come you don't have detention?
Gaz: "Strickland was, like, too busy chewin' out some other sap and didn't notice, so I got away with it!"
Dave: "You
jammy cunt!"
