Lock star re-uses regularly (5)
I believe the answer is:
tress
'lock' is the definition.
(I've seen this before)
'star re-uses regularly' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'star'+'re'+'uses'='starreuses'
The alternating letters of 'starreuses' are 'TRESS'.
(Other definitions for tress that I've seen before include "Curl - lock" , "Bit of hair" , "Long piece of hair" , "Long lock or plait of hair" , "Obsolete support" .)