Related Clues:

• You may step on it in a rush
• Sphere, say
• Fossil fuel
• Oven fuel
• Fill-up fluid
• Roadsign, perhaps
• Beetle juice
• Beetles go nowhere without it?
• Empty blather
• Stomach problem
• Physical state of ice
• Element like 8-Down
• Helium, e.g.
• Like a good alibi
• Main contents