Today's brief lesson is R-rated!
BAMF is an initialism. It stands for Bad Ass Mother Fucker. (Unless you're not my mom, aren't you glad that I told you, and not your son, the senior in college?)
BAMF is pronounced "bam-fph" or " It is not offensive to any specific groups of people, though it is probably not grandparents-approved. Like many inappropriate words, it is satisfying to say.
This is a term you use in earnest (as opposed to my ironic usage of YOLO). When you are feeling especially bad ass, feel free to call yourself a BAMF. You have my permission, Old People.
For reasons that are both untrue and unclear, Googling "BAMF" will lead you to articles about Dane Cook. I can not conclusively prove the levels of Cook's bad-assery.
BAMF, Urban Dictionary