Cutting a crossing (5)
I believe the answer is:
axing
'cutting' is the definition.
(I've seen this before)
'a crossing' is the wordplay.
'crossing' becomes 'xing' (I am not sure about this - if you are sure you should believe this answer much more).
'a'+'xing'='AXING'
Can you help me to learn more?
(Other definitions for axing that I've seen before include "Chopping, wood or jobs say" , "Dismissing (employees)" , "Sacking" , "Reducing expenditure sharply" , "Cutting down" .)