Definition: Brennan is a fictional character from the TV show "Breaking Bad," played by Bryan Cranston, who is an anti-drug advocate. The term has various meanings: Brennan being a person, a person's name, or even the abbreviation for breaking down something into smaller parts. It's used figuratively and literally to emphasize that action should be taken swiftly and decisively, similar to when someone breaks through barriers in an effort to achieve their goal.
brennan