What is the meaning of the idiom " Hear someone out"?

The correct answer is Let someone complete what they are saying.

The idiom "hear someone out" means to listen to someone without interrupting them until they have finished saying what they want to say. It is often used in a context where someone is trying to explain their point of view, and they want to be sure that the other person has heard them out before making a judgment.

The other options are incorrect.

• Dismiss someone means to send someone away or to reject their ideas.
• Keep someone out means to prevent someone from entering or participating in something.
• Hear from distance means to hear someone or something from a long way away.