Related Clues:

• Unpopulated
• Like some batteries
• Dull, as a party
• Ton type
• "In the Dark" band's nickname, with "the"
• __ ringer
• Kind of ton
• In need of charging, as a cell phone
• Defunct
• Breathless?
• Beyond tired
• ___ as a doornail
• Powers-of-10 system
• System adopted by most of the world
• Very, very tired