Cross at hosts for displaying charm (6)
I believe the answer is:
amulet
'charm' is the definition.
(amulet is a kind of charm)
'cross at hosts' is the wordplay.
'cross' becomes 'mule' (I've seen this before).
'hosts' is an insertion indicator.
'mule' put into 'at' is 'AMULET'.
'for displaying' is the link.
(Other definitions for amulet that I've seen before include "Jewel to protect from witchcraft" , "Thing worn as charm against evil" , "Protective ornament" , "lucky defender" , "Protective trinket" .)