Overly fearful (8)
I believe the answer is:
paranoid
'overly fearful' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for paranoid that I've seen before include "Suffering delusions; road pain (anag.)" , "Suffering from delusions of persecution" , "Distrustful" , "Irrationally obsessed by fear etc" , "one given to suspicion" .)