One asked to distribute what's left.. (8)
I believe the answer is:
executor
'one' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'asked to distribute what's left' is the wordplay.
I cannot quite see how this works, but
'to' 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 executor that I've seen before include "Person who sees that a will is followed" , "Implementer of a will" , "One ensures terms of a will are carried out" , "One carrying out the deceased's wishes" , "Person appointed to carry out the terms of a will" .)