To put a wrong clause right is not sacred (7)
I believe the answer is:
secular
'not sacred' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for secular that I've seen before include "associated with those who are 21 [LAYMEN]" , "Not religious or sacred" , "without religion" , "Not connected with religion" , "Not spiritual" .)