Commonly used as an abbreviated way to say "for real".
Usually used in texting, as many people use as many abbreviations as possible.
It can be a form of agreement towards someone, or disbelief.
If you use it as disbelief you may put a question mark to emphasize that you're asking if they're being serious.
Friend 1: "yo dawg, my crush asked me out today!"
Friend 2: "fr?"
Ex. 2: )
Friend 1: "Damn it's coldoutside, we might freeze to death."
When you fail at something in life (eg. failing an exam or not getting a job), go home and spend an hour just standing in the shower, propping yourself up against the wall with your eyes on your feet.
Caleb knew the only thing to do after he didnt get prefect was take a failure shower.