Maybe I just missed it, but I don't recall seeing "mean" on this thread.
In the US, to say someone is mean signifies that they are rude, unpleasant, nasty.
I understand that in some countries, it means they are cheap or miserly (i.e. thy don't like to spend money).
A short story by Maeve Binchy, who is Irish, had me thrown for a loop until I figured this out.