A shortened form of "What the fuck do you mean?", largely used when the person using the phrase takes a comment in a negative way.

Anatidaephobia is defined as a pervasive, irrational fear that one is being watched by a duck. The anatidaephobic individual fears that no matter where they are or what they are doing, a duck watches.

Anatidaephobia is derived from the Greek word "anatidae", meaning ducks, geese or swans and "phobos" meaning fear.

What, exactly, are you trying to say? Say what (Mostly used in defense)

Or

I'm fairly certain that I either didn't hear you correctly, or that you best have misspoken about me by accident!

Or

Hold up, let me get this straight! Did i really hear you say, what I think I just heard you say? (Used in defense mostly)

1) Extreme confusion with a situation, almost in disbelief, even though you sort of know the answer. The usual reaction when a person says or does something extremely shocking.

Sometimes a Rhetorical Question

extreme shock at a lack of knowledge

(Fuck you mean) Actually as it sounds must be said in one word usually used to express a sense of disagreement