[{"Bold_text": "adjective", "List Items": ["Geology.noting or pertaining to a period of the Paleozoic Era, occurring from 570 million to 500 million years ago, when algae and marine invertebrates were the predominant form of life.", "of or relating to Cambria ;Welsh."]}, {"Bold_text": "noun", "List Items": ["Geology.the Cambrian Period or System.", "a native of Cambria ;Welshman."]}]