It's used in digging a little bit lower, possibly (6)
I believe the answer is:
trowel
'it's used in digging a little' is the definition.
I can't judge whether this defines the answer.
'bit lower possibly' is the wordplay.
'bit' becomes 't' (I can't explain this - if you can you should give a lot more credence to this answer).
'possibly' is an anagram indicator.
'lower' with letters rearranged gives 'rowel'.
't'+'rowel'='TROWEL'
Can you help me to learn more?
(Other definitions for trowel that I've seen before include "Potting tool" , "Plastering tool" , "Spreading implement" , "small digger" , "Scoop-shaped tool with short handle" .)