tank used for collecting and storing a liquid (as water or oil)
lake used to store water for community use
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"
a large or extra supply of something; "a reservoir of talent"
a service that an organization or a piece of equipment offers you; "a cell phone with internet facility"
something designed and created to serve a particular function and to afford a particular convenience or service; "catering facilities"; "toilet facilities"; "educational facilities"
a building or place that provides a particular service or is used for a particular industry; "the assembly plant is an enormous facility"
a natural effortlessness; "they conversed with great facility"; "a happy readiness of conversation"--Jane Austen