hydrant — an upright pipe with a spout, nozzle, or other outlet, usually in the street, for drawing water from a main or service pipe, especially for fighting fires.
microphone — an instrument capable of transforming sound waves into changes in electric currents or voltage, used in recording or transmitting sound.
microscope — an optical instrument having a magnifying lens or a combination of lenses for inspecting objects too small to be seen or too small to be seen distinctly and in detail by the unaided eye.
microwaves — an electromagnetic wave of extremely high frequency, 1 GH 3 or more, and having wavelengths of from 1 mm to 30 cm.
