Four inches
Something that is mediocre, but there's nothing you can do about it; when a person isn't happy with something but will be polite and accept it. The word originates from the idea that a four inch penis really isn't okay, but a normal partner's response in the moment would be a polite, "oh, it's four inches? That's fine." It's the only appropriate reaction when you've already hit the point of no return in a situation and there's no un-awkward way to back out of it.
Example:
"This date I'm on is four inches, it's fine." "The hookup situation I'm in is four inches, it's fine."
"This date I'm on is four inches, it's fine." "The hookup situation I'm in is four inches, it's fine."