Implements left in black stuff brought back (5)
I believe the answer is:
tools
'implements' is the definition.
(tool is a kind of implement)
'left in black stuff brought back' is the wordplay.
'left' becomes 'l' (common abbreviation).
'in' is an insertion indicator.
'black stuff' becomes 'soot' (I've seen this in another clue).
'brought back' says the letters should be written in reverse.
'l' placed into 'soot' is 'sloot'.
'sloot' in reverse letter order is 'TOOLS'.
(Other definitions for tools that I've seen before include "Implements used to carry out particular functions" , "Hand implements" , "'A bad workman blames his . . . . .'" , "Implements used in one's job" , "Devices or implements, as of the trade" .)