A kiss in middle of night causes cancelling (5)
I believe the answer is:
axing
'cancelling' is the definition.
'a kiss in middle of night' is the wordplay.
'kiss' becomes 'x' (X can represent a kiss).
'middle of night' becomes 'G' (middle letter of 'night').
'a'+'x'+'in'+'g'='AXING'
'causes' is the link.
(Other definitions for axing that I've seen before include "Dismissing (employees)" , "Cutting down" , "Chopping, wood or jobs say" , "Sacking" , "Reducing expenditure sharply" .)