SOLENOID

noun Etymology: French solénoïde, from Greek sōlēnoeidēs pipe-shaped, from Greek sōlēn pipe Date: 1827 a coil of wire usually in cylindrical form that when carrying a current acts like a magnet so that a movable core is drawn into the coil when a current flows and that is used especially as a switch or control for a mechanical device (as a valve), ~al adjective