Related Clues:

• Anaesthetic
• Old anaesthetic
• Gas - air - space
• Colourless flammable liquid
• Solvent - anaesthetic
• Anaesthetic - solvent
• Colourless, highly flammable liquid
• Solvent – anaesthetic
• One or the other losing one that knocks you out
• Colourless liquid used as a solvent
• A number coming from the Netherlands — could be three
• It's arranged in a six-sided ring
• Out-of-use anesthetic
• Aristotle's 'fifth element'
• Upper regions of space, figuratively