Wrinkled crone, initially by river, relaxed (7)
I believe the answer is:
creased
'wrinkled' is the definition.
('crease' can be a synonym of 'wrinkle')
'crone initially by river relaxed' is the wordplay.
'initially' says to take the initial letters.
'by' means one lot of letters go next to another.
'river' becomes 'r' (abbreviation).
'relaxed' becomes 'eased' (I've seen this before).
The first letter of 'crone' is 'c'.
'c'+'r'+'eased'='CREASED'
(Other definitions for creased that I've seen before include "Wrinkled, rumpled" , "Groovy" , "Needing to be ironed?" , "Folded" , "Needing ironing" .)