n.

1. 理由，原因，動機[C][U][（+for）][+（that）][+why][+to-v]
   The reason (that)/why she did it is still a mystery.

   她為什麼做那件事仍是一個謎。

   We have every reason to refuse.

   我們完全有理由拒絕。

   We have reason to believe that he was lying.

   我們有理由相信他是在撒謊。

   The reason for her absence was that she was ill.

   她之所以缺席是因為她病了。

2. 理性，理智；判斷力，推理[U]
3. 道理，情理；明智[U]
   Why won't you listen to reason?

   你為什麼不願聽從道理？

4. 正常心智，正常神志[U]

vi.

1. 推論，推理，思考
   He is good at teaching his students to reason.

   他擅於教導學生如何推理。

2. 勸說，規勸[（+with）]

vt.

1. 推論，推理[Y][+that]
   I reasoned that he did not come because his old car had broken down again.

   我推想他沒有來是因為他的老爺車又拋錨了。

2. 勸說[O][（+into/out of）]
   I reasoned him out of selling his house.

   我說服他不把房子賣掉。

3. 辯論，討論

n.

1. a cause, explanation, or justification.
   ▸good or obvious cause to do something:

   we have reason to celebrate.
   ▸Logic  a premise of an argument in support of a belief, especially a minor premise given after the conclusion.
2. the power of the mind to think, understand, and form judgements logically.
   ▸ (one's reason) one's sanity.
3. what is right, practical, or possible.

v.

1. think, understand, and form judgements logically.
   ▸ (reason something out) find a solution to a problem by considering possible options.
2. (reason with) persuade with rational argument.