Outlay upsetting Scot (4)
I believe the answer is:
cost
'outlay' is the definition.
(cost is a kind of outlay)
'upsetting scot' is the wordplay.
'upsetting' is an anagram indicator.
'scot' is an anagram of 'COST'.
(Other definitions for cost that I've seen before include "Come to" , "Total spent for goods or services" , "Be priced at" , "Fee" , "Outlay required to buy" .)