The expression tosser is especially associated with the slang of British English, as well as the varieties of English it’s influenced around the world, including Irish and Australian English. It’s especially used as an insult for men.

Next we have “tosser”, a common insult that is certainly a lot less mild than the one above. If you call someone a tosser then this is generally a pretty serious insult, though it’s nothing extreme. A tosser is an objectionable or obnoxious person, someone you don’t like for one reason or another.