Related Clues:

• Sense-dulling drug
• Frequent encl.
• Encl. with a manuscript
• It may induce relaxation
• Editor's request
• Ltr. writer's courtesy
• Common enc.
• Sedative
• Drug
• Depressant
• Return env.
• Mind boggler
• Response facilitator: Abbr.
• Encl. for a reply
• It can knock you out