Sacred hearts not breaking any laws (8)
I believe the answer is:
hallowed
'sacred' is the definition.
(similar in meaning)
'hearts not breaking any laws' is the wordplay.
'hearts' becomes 'h' (abbreviation used in card games e.g. bridge).
'not breaking any laws' becomes 'allowed'.
'h'+'allowed'='HALLOWED'
(Other definitions for hallowed that I've seen before include "Sanctified" , "Reverenced" , "Like saints" , "Made holy and honoured" , "Respected" .)