Someone who's laughed at because they assume they're a boss or an important figure!
An actor, fake, flaw ass nicca in the hood.
Dee: What's up boss man - with a weird/devilish grin*
It can also be defined to the equivalent of the phrase, "Cool guy".
Sure, whatever you say boss man.
What can I do for you today, boss man?
"He's the Bossman, and I wouldn't get on his badside. I heard he once took on an entire street gang with only a car, his older brother, and a hammer, and manged to get away with only a totaled window."
"Wow, he's a badass!"