粵典 (words.hk)香港短語
形容啲人講到自己係專家噉，其實只不過係亂咁講 (to bullshit as if one is the expert; to speak from one's ass; literally, casual words taken as the bible)
語句用例
佢乜都唔識，就喺度隨口噏當秘笈。
keoi5 mat1 dou1 m4 sik1, zau6 hai2 dou6 ceoi4 hau2 ngap1 dong3 bei3 kap1.
He knows absolutely nothing and he's speaking nonsense.