Regime initially brought in stops wrinkles (7)
I believe the answer is:
creases
'wrinkles' is the definition.
(I know this)
'regime initially brought in stops' is the wordplay.
'regime initially' becomes 'r' (I can't justify this - if you can you should give a lot more credence to this answer).
'brought in' means one lot of letters goes inside another.
'stops' becomes 'ceases' ('cease' can be a synonym of 'stop').
'r' placed into 'ceases' is 'CREASES'.
Can you help me to learn more?
(Other definitions for creases that I've seen before include "Cricket lines" , "Pressed lines or crinkles" .)