Black shaded binding is discarded (10)
I believe the answer is:
jettisoned
'discarded' is the definition.
(jettisoning is a kind of discarding)
'black shaded binding is' is the wordplay.
'black' becomes 'jet' ('jet' can be similar in meaning to 'black').
'shaded' becomes 'toned'.
'binding' means one lot of letters goes inside another.
'toned' placed around 'is' is 'tisoned'.
'jet'+'tisoned'='JETTISONED'
(Other definitions for jettisoned that I've seen before include "Thrown away" , "Ditched" , "Thrown overboard" , "Discarded" , "thrown out of plane" .)