Related Clues:

• They mean nothing
• Six in 1,000,000
• Most of a 1,000,000,000
• Nonentities
• Binary system digits
• Plenty of nothing
• A googol has 100
• ''Goose eggs''
• Most of 1,000,000
• There are six in a million
• ''1001 Arabian Nights'' characters
• Head of zoo's love for ducks
• Naughts
• Noughts
• They end round numbers