When bro is "zum" with it.
A colloquial idiom similar to the phrase, "what the fuck is bro yapping about".
Can also be used randomly in any context as a filler word or as a compliment.
"bro's zum with it", is also a prime example of a non-sequitur comment.
Bzcutz: "bro summited mount Zum walked down and summited again."
Cfucutz: "bro was born in Zum Zum city and walks over mount Zum to the Zum Zum restaurant to eat Zum food."
Rwcutz: "bro's zum with it."