Depending on the use of the word in the sentence, expenditure can mean:
A. The manner in which you spend funds- this is how the funds are spent. Usually with sentences like “The expenditure of funds was so disappointing and sudden.”
B. The amount of the money you spend- this is the money you give in exchange for goods and/or services that you agreed when paying. Expenditures can be evidenced by various documents such us receipts, invoices, and other vouchers. “Let us reduce our expenditure.” Would be a good example.