Secret store of wood found by saint (5)
I believe the answer is:
stash
'secret store' is the definition.
(I've seen this in another clue)
'wood found by saint' is the wordplay.
'wood' becomes 'ash' (wood from an ash tree).
'found by' means one lot of letters go next to another.
'saint' becomes 'st' (abbreviation).
'ash' after 'st' is 'STASH'.
'of' is the link.
(Other definitions for stash that I've seen before include "Secret store of valuables" , "Hide (something) away" , "(Illegal) hoard" , "Hide in a secret place" , "(Hidden store of) drugs" .)