A portmanteau of the words "bro" and "rave".
A rave, or rave-like event, where the participants are mostly of the breed of men known lovingly as "Bro".
Broaves tend to feature the current electronic music on the harder, more bass-heavy spectrum of the macro-genre (read: jungle back in 2001; electro-house, in 2004; dubstep (bro-step), in 2011/12).
Broaves reflect the local Bro-scene and the typical Bro in a geographical area. Cities -- particularly college towns -- with bros of the asshole nature tend to have broaves filled with asshold bros.
Usage Note -1: Some people use "broave" to refer simply to events where the men outnumber the women considerably (see "sausage fest"); however, this usage is frowned upon by 9 out of 10 of our usage counsel and should not be used in this manner. (See also "Usage Note -2" below.)
Usage Note -2: A gay bar and circuit events, by their very definition, cannot be considered a "broave"; however, plenty of gay bars and circuit events (primarily gay one-off/warehouse events) have been overrun by "Bro". In this case, 7 out of 10 of our usage counsel agree that it is okay in the latter case to refer to a gay bar or circuit event as a "broave". Nota Bene: This usage is highly disputable, and should only be used in cases where the Bros are especially attractive and flirtatious.
"Lots of Bros there."
"Man, that place is turning into a broave."