<p><strong>Noun</strong></p><ul><li>A highway, as in a mountainous area, having many hairpin curves.</li><li>A zigzag track arrangement for climbing a steep grade.</li><li>British: roller coaster.</li></ul><p><strong>Verb</strong></p><ul><li>(used without object) (of a road, railroad track, etc.) to progress through a series of hairpin curves; zigzag: The road switchbacks up the mountain.</li></ul>