What is a AAA game?

[Megaoverlord12]

I preface this by saying I know it doesn't matter, and that I know we shouldn't necessarily be categorizing games as such; but we do anyway, so I'm just curious as to how. 

What makes a game AAA? We see the phrase thrown around a lot, from critics and journalists to normal consumers, but what does it actually mean? Is it budget? Is it development team? Is it development length? Is it based on the publisher? Developer? Can an indie game be AAA? Can a game become AAA, either during development or after? Are there series that are automatically AAA? And if true, are spin-offs of those series automatically AAA? Does sales performance mean anything? Expectations of sales? Price? Is it marketing? Does consumer prereception or hype mean anything? Does critical reception count? Does a game have to hit a retail store to be AAA? I hear games ranging from your yearly Call of Duty to Destiny to Deus Ex: Mankind Divided be called AAA, yet there is a large gap in... a LOT of ways between the three games. 

My personal thought on what entails AAA is a game with 2 of the following 5 criteria:

1. A high budget (As much as I'd love to define what I mean by that, publishers and developers almost never reveal their budget for any given game, so I have no idea what a high budget for a game is. I'd guess, $40 million+?)

2. High marketing spend (again, don't know a number for this)

3. A large dev team

4. Have expectations of over a million sales

5. High prerelease anticipation or hype from fans

Those are all fairly nebulous qualifiers, right? That's why I'm kinda interested in coming to a definition of sorts. I'm collecting the thoughts of many, from emailing game critics and journalists and asking in forums.