Fear of imitation ale, some might say (6)
I believe the answer is:
phobia
'fear' is the definition.
(a phobia is a fear of a particular thing)
I don't understand how the rest of the clue works.
(Other definitions for phobia that I've seen before include "Obsessive and persistent fear of something" , "Abnormal lasting fear or anxiety" , "An irrational fear or dislike" , "A lasting abnormal fear of smoething" , "A lasting abnormal fear or dislike" .)