Wrong spring in lock (8)
I believe the answer is:
trespass
'wrong' is the definition.
(I've seen this in another clue)
'spring in lock' is the wordplay.
'spring' becomes 'spa' (spa can mean a mineral spring).
'in' is an insertion indicator.
'lock' becomes 'tress' (both can mean a piece of hair).
'spa' placed inside 'tress' is 'TRESPASS'.
(Other definitions for trespass that I've seen before include "Encroachment" , "Enter land without permission" , "Enter someone's property unlawfully" , "Transgress" , "Enter another's property unlawfully" .)