Slang meaning horse-fucker in Hungary. Similar to bhenchod which is slang used to mean sister-fucker in India and Pakistan, this term is used as an insult.
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!