Related Clues:

• Opposite of full
• Pointing to E
• Like idle words
• One end of a gas gauge
• Containing nothing
• Uninhabited
• Ready for a refill
• Totally drained
• Jackson Browne's "Running on ---"
• It's hard to run on it
• Like a bottle ready to be recycled
• Having nary a drop
• Blank
• Like recycled bottles
• Worthless, as threats