Track fox discovered in wood (6)
I believe the answer is:
groove
'track' is the definition.
(thesaurus)
'fox discovered in wood' is the wordplay.
'fox' becomes 'o' (I can't explain this - if you can you should give a lot more credence to this answer).
'discovered in' means one lot of letters goes inside another.
'wood' becomes 'grove' (a grove is a small wood).
'o' inserted into 'grove' is 'GROOVE'.
Can you help me to learn more?
(Other definitions for groove that I've seen before include "Cut channel - set routine" , "Long narrow depression - dance and/or play popular music" , "Long shallow depression or routine" , "Long narrow channel in surface of hard material" , "Kind of furrow or rut" .)