reservoir

nouns

a large or extra supply of something
"a reservoir of talent"
reservoir
is a type of (narrower)
an amount of something available for use
supply
lake used to store water for community use
artificial lake, man-made lake, reservoir
tank used for collecting and storing a liquid (as water or oil)
reservoir
is a type of (narrower)
a large (usually metallic) vessel for holding gases or liquids
storage tank, tank
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"
reservoir, source