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 cold outside, we might freeze to death."
Friend 2: "yeah, fr."