Related Clues:

• Codeine, for one
• Narcotic
• Poppy plant derivative
• Downer
• Chloral hydrate, e.g.
• Calmer
• Sleep-inducing
• Painkiller
• Sleep inducer
• It will knock you out
• Soporific
• It'll knock you out
• Duller of the senses
• Sense dulling drug
• Cocaine, for one