Made sure lunatic is restrained (8)
I believe the answer is:
measured
'restrained' is the definition.
(I've seen this before)
'made sure lunatic' is the wordplay.
'lunatic' indicates an anagram.
'made'+'sure'='madesure'
'madesure' is an anagram of 'MEASURED'.
'is' acts as a link.
(Other definitions for measured that I've seen before include "Dare Muse be regular in movement" , "Made sure (anag.)" , "Unhurried and with care and dignity" , "Metered" , "Determined the dimensions" .)