뭐

1. what; oh my goodness; oh my gosh
An exclamation used when the speaker is surprised.

2. what
An exclamation used as an answer to someone's call, which means 'what is the matter?'.

3. well; you know
An exclamation used to refute the other party's opinion lightly or to inform him/her of a new piece of information.

4. anyway
An exclamation that a child or woman adds to the end of his/her words when acting like a baby playfully.

5. oh well; anyway
An exclamation used to indicate that it is useless to say anymore, when the speaker accepts a certain fact resignedly.