look up any word, like plopping:
 
1.
To freestyle rap out of nowhere on a moments notice.
Ej can strait freakin bust a flow out of no where.
by Darren Blatt August 26, 2006
 
2.
to suddenly become very agitated or irritable, as if one's period started.
Sorry man, but my mom is going to bust a flow if you come over.
by ru paulie April 26, 2009