reservoir
     n 1: a large or extra supply of something; "a reservoir of
          talent"
     2: lake used to store water for community use [syn: {artificial
        lake}]
     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"
        [syn: {source}]
Source: WordNet® 2.0