Police force in Channel Islands correct to get cross (8)
I believe the answer is:
crucifix
'cross' is the definition.
(I know that crucifix is a type of cross)
'police force in channel islands correct' is the wordplay.
'police force' becomes 'ruc'.
'in' is an insertion indicator.
'channel islands' becomes 'CI'.
'correct' becomes 'fix' (fix can mean to improve or correct).
'ruc' inserted inside 'ci' is 'cruci'.
'cruci'+'fix'='CRUCIFIX'
'to get' is the link.
(Other definitions for crucifix that I've seen before include "Necklace popular with Christians" , "Christian symbol" , "The Christian cross" , "Religious cross" , "Representation of the cross on which Jesus died" .)