How to say "what does this mean"?
What does this mean?
What is the meaning of this word?
What is this ( object )?
What did you say? ( not in a rude way )

Question

How to say "what does this mean"?
What does this mean?
What is the meaning of this word? 
What is this ( object )?
What did you say? ( not in a rude way )

Answer

무슨 뜻인가요?
이 단어의 뜻은 무엇인가요?
이것은 무엇입니까?
뭐라고 하셨나요?
(if you want to say could you repeat, 다시 한 번 얘기해주세요.)