Curb criminal element that's gripping area (7)
I believe the answer is:
contain
'curb' is the definition.
(I know that curb can be written as contain)
'criminal element that's gripping area' is the wordplay.
'criminal' becomes 'con' (short for convict).
'element' becomes 'tin' (tin is a kind of element).
'that's gripping' is an insertion indicator (inserted letters are gripped).
'area' becomes 'a' (maths abbreviation).
'tin' placed around 'a' is 'tain'.
'con'+'tain'='CONTAIN'
(Other definitions for contain that I've seen before include "Hold within, suppress (7)" , "keep within bounds" , "Accommodate" , "I cannot (anag) - hold back" , "Control, restrain" .)