1. Someone who is deliberately vague or unclear: Mr. White, the mayor, was accused of being a professional obscurantist because he refused to meet with the press and he denied public access to the city council meetings.
2. A person who is opposing or hindering the spread of new ideas and new social or political developments: Mr. Johnson, the prime minister of the country, was considered to be an obscurantist who was continually operating under a cloak of secrecy.