A unit of a human that causes exacerbation and distress to colleagues and other unfortunate humans of which it chooses to interact. Commonly referred to as a tank or big old slut, the human fridge is one of which should be avoided at all costs. Nothing comes good of the human fridge.
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!