(xiehouyu) To be incredibly bold or audacious. This is a pun on the literal image of tying chicken feathers to a flagpole to make a massive feather duster 鸡毛掸子 jī​máo​dǎn​zi. The word for duster, 掸子 dǎn​zi, sounds like the word for courage or gall, 胆子 dǎn​zi.