Temptation to break a rule (4)
I believe the answer is:
lure
'temptation' is the definition.
(lure is a kind of temptation)
'break a rule' is the wordplay.
'break' indicates an anagram.
'rule' with letters rearranged gives 'LURE'.
'to' is the link.
(Other definitions for lure that I've seen before include "It's used to attract fish" , "Attract with bait" , "Entice, bait" , "Tempt invoking rule" , "Enticement" .)