[{"Bold_text": "adjective", "List Items": ["inconceivable; unimaginable:the unthinkable size of the universe.", "not to be considered; out of the question:Such a suggestion is unthinkable."]}, {"Bold_text": "noun", "List Items": ["something that cannot be conceived or imagined, as something too unusual, vague, or disagreeable:Today's unthinkables are tomorrow's realities."]}]