「隨口噏當秘笈」

(pos:語句)
<explanation>
yue:形容啲人講到自己係專家噉，其實只不過係亂咁講
eng:to bullshit as if one is the expert; to speak from one's ass; literally, casual words taken as the bible
<eg>
yue: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.)
eng:He knows absolutely nothing and he's speaking nonsense.