Insult that was made relatively popular in England through it's use in the TV comedy series Red Dwarf. Essentially means a fool. See also numpty and prick.
Well, like a gimp but worse. It means as well as being a fool, retarded and just plain stupid, everyone knows it except you and you keep on believing your soooooo good BUT YOU'RE NOT!!
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!