1. Something that causes consternation.
2. A difficult, annoying or time consuming task.
3. To experience the sensation of pain in one's rectum.
1. Old people in supermarkets are a real arse ache.
2. Putting up that tent is going to be an absolute arse ache.
3. I didn't crap for a week and now I have a major arse ache.
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!