Definition
To speak disrespectfully or critically about someone, especially when they are not present, often with a tone of scorn or irreverence.
肆講別人（尤指在背後）
She dislikes being criticized publicly, especially having her name taken in vain behind her back.
她不喜歡被公開批評，尤其討厭別人在背後不尊重地談論她。
During the meeting, he tried to take his opponent's name in vain with a contemptuous tone, but his colleagues found it inappropriate.
在會議中，他試圖用輕蔑的語氣不尊重地談論對手，但同事們認為這很不恰當。
They took their neighbors' names in vain freely at the dinner table, showing a clear lack of respect.
他們在餐桌上隨意不尊重地談論鄰居，明顯缺乏尊重。