+0
Is there a difference between the following sentences:

What does hydrophobic mean?
What means hydrophobic?
1 2
Comments  (Page 2) 
Thank you, that was a good explanation. I now understand the difference between the two sentences.

What about, "What hydrophobic means"? is that wrong or informal?

Students: We have free audio pronunciation exercises.
anonymous

What about, "What hydrophobic means"? is that wrong or informal?

It is a content clause, not a sentence.

e.g. I know what hydrophobic means.