British / American translations...

[Stephen]

Just a few translations for those yanks (like myself) that enjoyed this story


anorak / a hooded pullover jacket
biro / BIC style ballpoint pen
jaffa cake / Round, coaster sized sponge cake snack with Orange jam covered in chocolate
jumper / sweater
picnic eggs / deviled eggs
pillock / stupid person (with an etymologically penile roots) the US equivalent would be calling someone a "dick"
plonk / cheap wine
plonker / Dope, idiot, etymologically a drunk
prat / dumbass

Ronnie Biggs - One of the fellows responsible for the great Train Robbery

[Roger]

"pillock" is really synonymous with "bollocks", being "balls" or "testicles". In shortened form used as in: "He kicked the other lad in the pills." Like most such usage, all these also mean "stupid person" almost by definition!

Both "plonker" and "prat" are also synonymous with "cock", "dick", et al