[{"Bold_text": "adjective", "List Items": ["resembling or containing chalk.", "(initial capital letter)Geology.noting or pertaining to a period of the Mesozoic Era, from 140 million to 65 million years ago, characterized by the greatest development and subsequent extinction of dinosaurs and the advent of flowering plants and modern insects."]}, {"Bold_text": "noun", "List Items": ["(initial capital letter)Geology.the Cretaceous Period or System."]}]