reservoir
🇺🇸
/ˈrezərvwɑːr/
🇬🇧
/ˈrezəvwɑː(r)/
A large natural or man-made lake that stores water for people to use.
The city gets its drinking water from a large reservoir in the mountains.
A large supply of something that can be used when needed.
The internet is a huge reservoir of knowledge and information.
A container in a machine that holds liquid before it is used.
Check the oil reservoir before starting the engine.