Fear beginning to dwindle, say (5)
I believe the answer is:
dread
'fear' is the definition.
(I know that dread is a type of fear)
'beginning to dwindle say' is the wordplay.
'beginning to' says to take the initial letters.
'say' becomes 'read' (synonyms).
The initial letter of 'dwindle' is 'd'.
'd'+'read'='DREAD'
(Other definitions for dread that I've seen before include "Be afraid of - anxiety" , "Terror" , "Anticipate with fear" , "Anticipate with horror" , "Hairstyle" .)