Related Clues:

• Drug served in a den
• Heroin, for one
• Morphine or codeine, e.g.
• Religion, to Marx
• Narcotic from poppies
• Religion, to the masses, per Marx
• Deadening agent
• What might be a knockout?
• A sedative drug
• A poet I become on this drug
• It induces sleep
• Preparation made from poppy derivative
• A sleep-inducing drug
• A drug to induce sleep
• It's used as medicine or narcotic