Group of three attempt to kidnap popular Italian (7)
I believe the answer is:
trinity
'group of three' is the definition.
(I've seen this before)
'attempt to kidnap popular italian' is the wordplay.
'attempt' becomes 'try' (I've seen this before).
'to kidnap' means one lot of letters goes inside another.
'popular' becomes 'in'.
'italian' becomes 'it'.
'in'+'it'='init'
'try' placed around 'init' is 'TRINITY'.
(Other definitions for trinity that I've seen before include "House" , "Group of three considered as one" , "Term" , "Cambridge college founded by Henry VIII" , "A group of three people" .)