[{"Bold_text": "adjective", "List Items": ["characterized by youth ;young.", "of, relating to, or befitting youth:youthful enthusiasm.", "having the appearance, freshness, vigor, etc., of youth:She is 60 but her optimism has kept her youthful.", "in an early period of existence; early in time.", "Physical Geography.(of topographical features) having undergone erosion to a slight extent only."]}]