lubrication payment

noun1

1. •
   (euphemistic) A bribe or extorted money, usually relatively small in amount, provided to a low-level government official or business person, in order to expedite a business decision, shipment, or other transaction, especially in a country where such payments are not unusual.

   • A lubrication payment is a small payment to low-level business people or government officials to "grease the wheels" of business. — 1995