Caution in woods circling one empty gulch (9)
I believe the answer is:
foresight
'caution' is the definition.
(I've seen this before)
'woods circling one empty gulch' is the wordplay.
'woods' becomes 'forest' (synonyms).
'circling' is an insertion indicator (circling can mean going around or containing).
'one' becomes 'I' (Roman numeral).
'empty' says to hollow out the word (remove centre letters).
'gulch' with its centre taken out is 'gh'.
'i'+'gh'='igh'
'forest' going around 'igh' is 'FORESIGHT'.
'in' is the link.
(Other definitions for foresight that I've seen before include "Vision" , "Planning" , "Caution" , "Anticipation" , "Prudence" .)