A made up word used by an uneducated individual who doesn't like when their verbal grammer errors are pointed out to them. Directed toward the person who corrected them.
*Calls phone number, but no one picks up the phone *
"Uh, It didn't work."
"You mean, no one answered the phone."
"You're an exactist."
"You're an idiot, that's not even a word."
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!