Understanding fear (12)
I believe the answer is:
apprehension
I believe this is a double definition.
'understanding' is the first definition.
(I know that understanding can be written as apprehension)
'fear' is the second definition.
(I know that apprehension is a type of fear)
(Other definitions for apprehension that I've seen before include "Understanding; anxiety" , "Fear" , "The catching" , "Arrest -- dread" , "Uneasy concern" .)