Cut made in Christmas liturgy (4)
I believe the answer is:
slit
'cut' is the definition.
(I know that slit is a more specific form of the action cut)
'in christmas liturgy' is the wordplay.
'in' indicates the answer is hidden within the clue.
'SLIT' is hidden within 'christmas liturgy'.
'made' acts as a link.
(Other definitions for slit that I've seen before include "Incision" , "Narrow rent" , "Narrow aperture" , "Long straight cut" , "Long narrow opening" .)