A fork of Rural Dictionary
Stands for "foot in mouth", which is when you say something incredibly awkward without giving it much thought beforehand.
"I totally had a FIM moment last night at Evan's party."
(F)uck (I)t (M)entality; (letters are spoken, it is not said as it sounds) When you are absolutely making a bad decision, but you decide to go through with it anyway because why tf not. The time for regret is on your deathbed.
“Should I do it?”
“Yeah man, FIM! Fuck it mentality!”