Slang term in Britain from ca. 1825: what would it have meant to refer to someone as a TON?

I think you might mean a Tom. This is slang for a prostitute. It comes from Cockney rhyming slang, a 'Tommy Tucker' is a 'f*cker' Tom for short. A Ton is slang for 100, either £100 or 100 m.p.h.

You would not describe a person as "a ton". A person could be described as a "member of the ton", meaning that they were probably aristocratic and that they knew and mixed with all the right people.

They could also be described as "having good ton", meaning they were the kind of person who did things they way people of the ton did them.

http://www.en.wkipedia.org/wiki/Ton_(le_bon_ton)

The word ton was an adjective. It was used to describe something that was popular, stylish, trendy, fashionable, all the rage, etc. As in, "this year, spike heels are the ton."

Thanks for the quick response. I know those, but it may be that the person who asked me typed the word incorrectly. I'll check with her.