British English vs. American English.
I just learned what a "tosser" is for the first time. Nifty!→
[More:]My English friend just clued me in...I never knew that's what it meant! Better late than never.
I'm always fascinated by the linguistic differences over the big pond. What's even more interesting is that I don't think Americans have an insult that is equivalent to "someone who masturbates". Maybe a "jerkoff", but that's not used nearly as often as tosser or wanker, I don't think.