[{"Bold_text": "adjective", "List Items": ["of, relating to, or resembling a planet the planets .", "wandering; erratic.", "terrestrial; global.", "Machinery.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."]}, {"Bold_text": "noun", "List Items": ["Machinery.a planetary gear train."]}]