Definitions

1. noun

a large artificial or natural container for storing liquid, especially water, or for storing something else, such as coal or oil

“The city’s water supply comes from a large reservoir in the nearby mountains.”

2. noun

a supply or store of something, especially a large or secret supply

“The government had a reservoir of funds to use in case of an economic downturn.”

3. noun

a device or system that stores energy, such as electrical energy, in a magnetic field or in a capacitor

“The power company uses a reservoir of electricity to regulate the flow of power to the grid.”