Related Clues:

• It can put you out
• Anesthetic liquid
• Erstwhile anesthetic
• Outmoded anesthetic
• Compound number?
• Novocain predecessor
• Old surgery aid
• Air or heavens, to a poet
• Air beyond the clouds
• Inhaled anesthetic of old
• Fifth classical element
• Onetime dental anesthetic
• One on it may be out of it
• Clear blue sky
• Operating room substance, once