Church has silver pen (4)
I believe the answer is:
cage
'pen' is the definition.
(thesaurus)
'church has silver' is the wordplay.
'church' becomes 'ce' (abbreviation for Church of England).
'has' is an insertion indicator.
'silver' becomes 'ag' (Ag is the chemical symbol for silver).
'ce' placed around 'ag' is 'CAGE'.
(Other definitions for cage that I've seen before include "Confine -- US composer, d. 1992" , "Incarcerate" , "US composer -- barred enclosure" , "Barred container" , "Nicolas - - (films)" .)