Cancelling hair-removal treatment after losing weight (5)
I believe the answer is:
axing
'cancelling' is the definition.
'hair-removal treatment after losing weight' is the wordplay.
'hair-removal treatment' becomes 'waxing'.
'after losing' indicates named letters should be taken away.
'weight' becomes 'w'.
'waxing' with 'w' removed is 'AXING'.
(Other definitions for axing that I've seen before include "Reducing expenditure sharply" , "Chopping, wood or jobs say" , "Dismissing (employees)" , "Cutting down" , "Sacking" .)