The running costs of a business are the amount of money that is regularly spent on things such as salaries, heating, lighting, and rent. [business]
The aim is to cut running costs by £90 million per year.
2. plural noun
The running costs of a device such as a heater or a fridge are the amount of money that you spend on the gas, electricity, or other type of energy that it uses.
Always buy a heater with thermostat control to save on running costs.