Related Clues:

• It's inert
• Odorless, colorless, inert gas
• Laser gas
• Colorless gas
• Vacuum tube gas
• Fluorescent bulb filler
• A noble gas
• Chemical element
• Element whose name comes from Greek for 'inactive'
• One of the 6 noble gases
• Light gas
• Air element
• Gas in bulbs
• Rare gas
• Element whose name roughly means 'lazy'