Fear demoralising beginner, say (5)
I believe the answer is:
dread
'fear' is the definition.
(I know that fear can be written as dread)
'demoralising beginner say' is the wordplay.
'beginner' suggests taking the first letters.
'say' becomes 'read' (synonyms).
The initial letter of 'demoralising' is 'd'.
'd'+'read'='DREAD'
(Other definitions for dread that I've seen before include "great anxiety" , "Get cold feet" , "Affright" , "Deep fear" , "Hairstyle" .)