[{"Bold_text": "noun", "List Items": ["(often initial capital letter)Greek History.any of a class of professional teachers in ancient Greece who gave instruction in various fields, as in general culture, rhetoric, politics, or disputation.a person belonging to this class at a later period who, while professing to teach skill in reasoning, concerned himself with ingenuity and specious effectiveness rather than soundness of argument.", "any of a class of professional teachers in ancient Greece who gave instruction in various fields, as in general culture, rhetoric, politics, or disputation.", "a person belonging to this class at a later period who, while professing to teach skill in reasoning, concerned himself with ingenuity and specious effectiveness rather than soundness of argument.", "a person who reasons adroitly and speciously rather than soundly.", "a philosopher."]}]