Maintenance and Per diem

Maintenance noun - The act or activity of keeping something in an existing and usually satisfactory condition.

Per diem and maintenance are semantically related. In some cases you can use "Per diem" instead a noun "Maintenance".

Per diem noun - A daily allowance for living expenses (especially while traveling in connection with your job).

Maintenance and per diem are semantically related. Sometimes you can use "Maintenance" instead a noun phrase "Per diem".