1: another word for vagina. comes from the bloodhound gang's song "Foxtrot Uniform Charlie Kilo".
2: an all-girl band from Knoxville, TN. ref: www.myspace.com/gutlocker69
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!