The dictionary gives the definition of: "Toff," as:I only know what you mean by "toff" because of this line from "To Sir, With Love:"
Etymology. The word "toff" is thought to come from the word "tuft", which was a gold tassel worn by titled undergraduates at the University of Oxford or the University of Cambridge. The Anglo-Saxon word "toforan" has a meaning of "superiority".
Notice it describes the undergraduate as titled, that usually means an inherited moniker like Lord. However, if like me, you are from humble stock and just a common or garden undergraduate, that's if you were lucky enough to make it to university, your definition off toff would be altogether more disparaging.
As those with an air of superiority had a certain swagger, we of the raggedy set would say that the walk looked like they were chewing a toffee between their buttocks. That's about the cleanest way that I can describe it.