Crime of passion is initially risqué (6)
I believe the answer is:
piracy
'crime' is the definition.
(piracy is a kind of crime)
'passion is initially risque' is the wordplay.
'initially' says to take the initial letters.
'risque' becomes 'racy' (synonyms).
The initial letters of 'passion is' is 'pi'.
'pi'+'racy'='PIRACY'
'of' is the link.
(Other definitions for piracy that I've seen before include "Maritime or commercial robbery" , "theft" , "Robbery at sea or of copyright" , "Act of plagiarism" , "Copyright infringement" .)