Arab leader accepting last list of discussion items (6)
I believe the answer is:
agenda
'list of discussion items' is the definition.
(I've seen this before)
'arab leader accepting last' is the wordplay.
'arab leader' becomes 'aga' (title in some Muslim countries).
'accepting' means one lot of letters goes inside another.
'last' becomes 'end'.
'aga' enclosing 'end' is 'AGENDA'.
(Other definitions for agenda that I've seen before include "Schedule, order of business" , "List of items to be discussed" , "To-do list" , "List of items for discussion by committee" , "matters for discussion" .)