1) A term used to depict a time period where a lack of skill, ability, or performance was displayed. It is also used to mock people who "find the cheap way" to play games or perform tasks. This term can be used to many different types of situations.
Examples:
Applied to Work:
Boss: "Damn it Johnson! These papers are NOT in alphabetical order. What is this, Amateur Hour?"
Applied to Video Games:
Player A: "Wow, that kid is using a glitch. I forgot it was amateur hour this time of day."
Applied to Home:
Mom: "Rodney, your room is filthy. I thought I said clean it."
Son: "I did clean it."
Mom: "Did you clean it during amateur hour or something? This is atrocious!"
Applied to School:
Professor: "The class average was a D+ on this exam...seriously class, is it amateur hour when you all come here?"
A person you hate intensely not because they deserve such hatred but because they serve as a focus for your general hatred. A healthy way to dispense with excess animosity.
Jake's not really that big an asshole. He just serves as my hate sink.