(It’s a French song; very appropriate.)
Literally: bystander – possibly / (young) – nothing – person
Alternately: Doing or saying whatever the hell you want without caring that you’re in public. Acting however you feel like without consideration for the thoughts or feelings of one’s fellow humans. Arrogance. A complete lack of regard or empathy for others. In a word, presidential, ha ha ha.
Notes: Writing boujaku as 暴若 (no actual meaning) is an error, as is reading 無人 as mujin. However, replacing 傍 with 旁 is an acceptable variation.
This compound comes to us from the Records of the Grand Historian, a Han Dynasty era historical text. In a chapter on the biographies of assassins, it discusses one Jing Ke – who would later try and fail to assassinate the king of Qin – and his tendency, when drinking, to sing loudly or break down in tears and otherwise make a nuisance of himself.