a device for flushing toilets that uses system pressure rather than gravity and automatically shuts off after a measured amount of water flow in order to conserve water.
flush·om·e·ter (flŭsh-ŏm'ĭ-tər) n. A device for flushing toilets and urinals that utilizes pressure from the water supply system rather than the force of gravity to discharge water into the bowl, designed to use less water than conventional flush toilets.