When An Erect Male Lays on The Bad And Pulls His Erection Towards His Belly Button, And The Female Procceeds To Sit On HIs Now Horizontal Penis Causing A "Hotdog In A Bun" Situation
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!