Scruff last to gamble on tipster's choice (4)
I believe the answer is:
nape
'scruff' is the definition.
(synonyms)
'last to gamble on tipster's choice' is the wordplay.
'last to' suggests the final letters.
'on' says to put letters next to each other.
'tipster's choice' becomes 'nap' (I can't justify this - if you can you should believe this answer much more).
The last letter of 'gamble' is 'e'.
'e' after 'nap' is 'NAPE'.
Can you help me to learn more?
(Other definitions for nape that I've seen before include "Back part of the neck" , "Scruff of the neck" , "Girl personifying France" , "sofa" , "Scrag" .)