gibberish; nonsense; incomprehensible talk
A set phrase literally meaning 'a Chinese person's sleep talk', used to describe speech or writing that is completely unintelligible or nonsensical. Often carries a dismissive or humorous tone.
His explanation was complete gibberish; I had no idea what he was talking about.
Also means 'gibberish' or 'incomprehensible', but is a more common and neutral mimetic word, while 唐人の寝言 is a colorful set phrase with a historical flavor.
Literally 'a Chinese person's sleep talk'. The phrase reflects a historical perception that Chinese speech was difficult to understand, likening it to the unintelligible mumbling of someone talking in their sleep. The exact origin is uncertain, but it has been used as a set expression for nonsense or gibberish.