Sketch of Saint Christopher (4)
I believe the answer is:
skit
'sketch' is the definition.
(thesaurus)
'saint christopher' is the wordplay.
'saint' becomes 's'.
'christopher' becomes 'kit' (I've seen this in other clues).
's'+'kit'='SKIT'
'of' acts as a link.
(Other definitions for skit that I've seen before include "Parodic sketch" , "'Short comedy sketch, a parody (4)'" , "Hoax; satire" , "Comic sketch" , "piece of satire" .)