Related Clues:

• Like carbon monoxide
• Nonreactive, as some gases
• Like dead weight
• Nonreactive, chemically
• Like a dead weight
• Hard to get a reaction out of?
• Like a noble gas
• Chemically unreactive
• Motionless, still
• Motionless or lifeless
• Lifeless or static
• Motionless or inanimate
• Inter, being unable to move
• Lifeless, without power to move or act
• Slow and apathetic