Related Clues:

• 'No ___' ('Beats me')
• Invention impetus
• "The very" thing
• Inventors have them
• 'What's the big ___?'
• It may be preconceived
• Invention preceders
• Gray matter matter?
• It may be bright
• Coconut yield?
• Some are bright, some are dumb
• Think-tank nugget
• "I have an __!"
• Conceptions
• Head start?