reservoir UK /ˈɹɛz.ə.vwɑː/US /ˈɹɛz.ə(ɹ).vwɑɹ/noun 6verb 1forms 3 noun6 •A place where anything is kept in store.Within a printer cartridge, ink is typically stored in an ink reservoir and is deposited onto media through a print head. — 2013 •A large natural or artificial lake used as a source of water supply. •A small intercellular space, often containing resin, essential oil, or some other secreted matter. •A supply or source of something.To replace them and also to provide a reservoir for relief trains, a certain amount of spare stock must be kept on hand. — 1962 •A species that acts as host to a zoonosis when it is not causing acute illness in other susceptible species. •A "black box" component that receives an input signal to be read out and mapped by another process, as part of reservoir computing. verb1 •To store or keep (something) in or as in a reservoir. formsreservoired · reservoiring · reservoirs