reservoir

noun

1. a large or extra supply of something"a reservoir of talent"
2. lake used to store water for community use; a lake (natural or artificial) used to store water and used as a source of water
3. tank used for collecting and storing a liquid (as water or oil)
4. anything (a person or animal or plant or substance) in which an infectious agent normally lives and multiplies"an infectious agent depends on a reservoir for its survival"