Rodent round knotted tree in peaceful place (7)
I believe the answer is:
retreat
'peaceful place' is the definition.
'retreat' can be an answer for 'place' (I have seen 'secluded place' mean 'retreat' so perhaps 'place' could also mean 'retreat'). I'm not sure about the 'peaceful' bit.
'rodent round knotted tree' is the wordplay.
'rodent' becomes 'rat' (rat is a kind of rodent).
'round' is an insertion indicator.
'knotted' is an anagram indicator.
'tree' with letters rearranged gives 'etre'.
'rat' placed around 'etre' is 'RETREAT'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for retreat that I've seen before include "Climb down" , "Leave - refuge" , "place for meditation" , "The Priory, say" , "What cowards might do" .)