Part of a popsong on the simpsons in which 3 women chant it in a slow, kind of egyptian fashion. This is really just join the navy spelled backwards, designed for subliminal advertizing.
(Otto waiting for Navy bus)
Lisa: Hey Otto, what are you doing?
Otto: I dunno, I just got this craving to join the navy. Yvan eht nioj! (gets on bus)
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!