A growhawk is a mohawk that has grown out, and is almost undetectable, but still there; when the wearer is too lazy to get the sides shaved again, or has been forbidden to do so by his/her parents.
"Did you seeIan?" "Yeah, he's got a growhawk now, looked sweet in July, but he can't get it done again because school started last week."
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!