Delivered letter promoting area (5)
I believe the answer is:
dealt
'delivered' is the definition.
(I've seen this in another clue)
'letter promoting area' is the wordplay.
I cannot really see how this works, but
'letter' could be 't' and 't' is located in the answer.
'area' could be 'a' (maths abbreviation) and 'a' is found in the answer.
The remaining letters 'del' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for dealt that I've seen before include "Doled out" , "Traded" , "Delta (anag.)" , "Distributed playing cards" , "Carried out business" .)