Related Clues:

• Piece of mind?
• Seed of invention
• Green veggie
• What may come to mind
• Just think of it
• Prelude to a solution
• Brainy inspiration
• It may come to a head
• ''What's the big ___?''
• Genesis of an invention
• Inventor's flash
• ''It seemed like a good ___ at the time!''
• Certain fiber source
• It's in your mind
• It may be bright or big