Christopher's outfit (3)
I believe the answer is:
kit
This clue is a double definition.
'christopher's' is the first definition.
(short for Christopher)
'outfit?' is the second definition.
(I know that outfit can be written as kit)
(Other definitions for kit that I've seen before include "Old song 'Pack up your troubles in your old . . . bag'" , "tackle" , "Equipment, clothing" , "Apparatus" , "Set of parts sold to be assembled" .)