The most annoying little shit you can possibly imagine. Hangs around at Star Wars Galactic Battlegrounds Heaven, where he acts like an annoying pompous arsehole and pisses everyone but him and his poxy little friends off.
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!