Very great fear or dread (6)
I believe the answer is:
terror
This clue is a double definition.
'very great fear' is the first definition.
(I've seen this before)
'dread' is the second definition.
(synonyms)
(Other definitions for terror that I've seen before include "Ovewhelming fear" , "Panicky fright" , "Paralysing fear" , "Little brat" , "Sheer fright" .)