The person appointed to carry out the terms of a will (8)
I believe the answer is:
executor
'the person appointed to carry out the terms of a will' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for executor that I've seen before include "Man appointed by testator" , "Person nominated to carry out the terms of a will" , "Person who carries out the provisions of a will" , "One carrying out the deceased's wishes" , "Person appointed to carry out the terms of a will" .)