Leaves fuddy-duddy briefly to suppress trouble that's returning (7)
I believe the answer is:
foliage
'leaves' is the definition.
(I've seen this before)
'fuddy-duddy briefly to suppress trouble that's returning' is the wordplay.
'fuddy-duddy' becomes 'fogey' (I've seen this in another clue).
'briefly' means to remove the last letter.
'to suppress' indicates putting letters inside (inserted letters are suppressed or crushed).
'trouble' becomes 'ail' (synonyms).
'that's returning' says the letters should be written in reverse.
'ail' in reverse letter order is 'lia'.
'fogey' with its final letter taken away is 'foge'.
'foge' going around 'lia' is 'FOLIAGE'.
(Other definitions for foliage that I've seen before include "Mass of leaves" , "Greenery, leaves of trees or plants" , "Plant leaves collectively" , "Leaves of tree or plant" , "Green leaves" .)