To suffer an uncontrollable erection that tears through one's pantaloons. Only a select few suffer from this condition, which occurs each year by the light of the hunter's moon.
Though he may walk amongst us as a normal man, come the autumnal equinox he will summon the bone dragon, thereby revealing himself.
1) A member of the douche bag family that generally lacks social skills. Spends most nights concocting roofie cocktails and masturbating into their popped collars.
2) A primordial or lesser evolved douche bag
1) My girlfriend's neighbor was a total bone dragon, always hitting on her when I wasn't around. I had to slay him.
2) Look at that bone dragon acting like he's hot shit. He's got his Best Buy shirt collar popped.