Fear of Colonel Kurtz? (6)
I believe the answer is:
horror
'fear' is the definition.
(I know that horror is a type of fear)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for horror that I've seen before include "Extreme fear or revulsion" , "Intense shock" , "Great dismay" , "Extreme shock and revulsion" , "Feeling of panic and dread" .)