Hydrophobia (6)
I believe the answer is:
rabies
'hydrophobia' is the definition.
(I know that hydrophobia can be written as rabies)
This is all the clue.
(Other definitions for rabies that I've seen before include "make you hate water!" , "Disease transmitted through saliva" , "Dangerous viral disease" , "illness (like 13)" , "Name of disease from Serbia in 26 Down" .)