Boater, perhaps, that’s wasting time (3)
I believe the answer is:
hat
'boater perhaps' is the definition.
(boater is a kind of hat)
'that's wasting time' is the wordplay.
'wasting' suggests deleting specific letters.
'time' becomes 't'.
'that' with 't' taken away is 'HAT'.
(Other definitions for hat that I've seen before include "Headdress" , "Head-covering" , "Lid" , "e.g. Pork pie" , "Accessory" .)