To back out of something at the last minute. Similar to "pussy out." Derived from the word "flaccid," and pronounced "flass out." When one flacces out, his flaccing out is compared to his penis going soft right before a critical juncture in a sexual encounter.
Aaron: Hey bro I don't think I can come rage tonight, I'm feeling sick.
Bro: Aw come on man don't flacc out on me.
Chad: Hey dude why wasn't Aaron there last night?
Dude: Bro told me he flacced out at the last minute.
Chad: What a flacchole.
To be defeated in a feat of strength
He out-strengthed his opponents
When you, as a woman get the chance to be unhindered by the societal norms and constricting nature of pants (as well as braziers) and finally get the opportunity to unwind and "treat yoself" and "do you boo", allowing yourself to engage in a little "self-care".
It's been a rough week Deb, I think I'll go home, open a bottle of wine, turn on Gilmore Girls and "veg out with my hedge out."
Verb; the act of chillin with a group of your amigos and no one stressin bout anything.
Yeah Tyrone we finna doof out later at lunch