Choice digging tool (4)
I believe the answer is:
pick
This clue is a double definition.
'choice' is the first definition.
(synonyms)
'digging tool' is the second definition.
(tool used for digging)
(Other definitions for pick that I've seen before include "Select - implement" , "Choose - tool for breaking up ground" , "Pluck" , "Hero of a Dickens novel" , "The best tool" .)