Blade turned up in wastepaper basket (5)
I believe the answer is:
sabre
'blade' is the definition.
(sabre is a kind of blade)
'turned up in wastepaper basket' is the wordplay.
'turned up' shows that the letters should be reversed in order.
'in' says the answer is hidden in the clue.
'erbas' is hidden within 'wastepaper basket'.
'erbas' written backwards gives 'SABRE'.
(Other definitions for sabre that I've seen before include "Bares (anag.)" , "Heavy cavalry sword" , "Sword with curved blade" , "Slasher" , "Walt --, cartoonist" .)