To cry about, be afraid of, or complain about everything. To chicken out is to Brook out. Whining about something is Brooking about it.
Brooks are afraid of
girls, they Brook out when one talks to them. Usually when a
girl says hey to a Brook, a Brook will respond by saying something gay like 'yo'.
People who wish to bring someone out who acts like this will say 'don't be a Brook'.
Nobody wants to be a Brook.