An unexplainably large unit of measurement for when the exact amount is not known but it's probably more than estimated.
Dylan: You see, I have like... a predicament...
You: Of what sort?
Dylan: I have an unknown but incredibly large amount of jars full of, uh...
You: So you have a GADOMULUM of jars!?
...
You: Oh yeah, and they're full of, uh... A GADOMULUM OF, uh...
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!