<p><strong>Noun</strong></p><ul><li>An electric conductor wound as a helix with small pitch, or as two or more coaxial helices, so that current through the conductor establishes a magnetic field within the conductor.</li><li>Also called solenoid switch.</li><li>A switch controlled by such an arrangement, in which a metal rod moves when the current is turned on; used in automotive starting systems.</li><li>In meteorology, a space formed by the intersection of isobaric and isosteric surfaces.</li></ul>