Coming from the Irish word for sad (brón), prenounced Bro-Ner.
An upset or sad erection given by a friend. This does not have to be intentional by either party involved.
Peter: I was so depressed on Sunday afternoon in Marks.
Peter: Ah you know, Mark was slagging me and then he farted and for some reason I got a bróner.
John: Shit one dude.