<p><strong>Adjective</strong></p><ul><li>of, relating to, or resembling a planet or the planets.</li><li>wandering; erratic.</li><li>terrestrial; global.</li><li>noting or pertaining to an epicyclic gear train in which a sun gear is linked to one or more planet gears also engaging with an encircling ring gear.</li></ul><p><strong>Noun</strong></p><ul><li>Machinery: a planetary gear train.</li></ul>