ˈɹɛz.ə.vwɑː(ɹ) ˈɹɛz.ə(ɹ).vwɑɹ sɔɹs sɔːs tank used for collecting and storing a liquid (as water or oil) lake used to store water for community use; a lake (natural or artificial) used to store water and used as a source of water 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