Person engaged by cleaning company appearing with a line drawing (8)
I believe the answer is:
charcoal
'line drawing' is the definition.
(thesaurus)
'person engaged by cleaning company appearing with a' is the wordplay.
I cannot really understand how this works, but
'company' could be 'co' (abbreviation) and 'co' is located in the answer.
'a' is within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for charcoal that I've seen before include "Black residue of burnt wood" , "It's used in drawing and barbecues" , "Standard" , "Fuel used for drawing" , "Fuel made from burnt wood" .)