老师讨论用英语可以说是"teacher discussion"或"teacher-led discussion"。这个短语的来源可能是指由老师主导的讨论，在课堂上或其他场合。下面是一些英文例句和中文翻译：

"The teacher led a discussion about the importance of critical thinking in today's world."（老师主导了一个关于当今世界批判性思维重要性的讨论。）
"The teacher faciptated a pvely discussion among the students about the causes of the Civil War."（老师促进了学生们就内战原因进行活跃的讨论。）
"The teacher encouraged the students to participate in the discussion by asking thought-provoking questions."（老师通过提出发人深省的问题鼓励学生参与讨论。）

总之，"teacher discussion"或"teacher-led discussion"是指由老师主导的讨论活动。