Related Clues:

• Imagine that
• Productive thought
• One may be big or bright
• ''The very ___!'' (''What nerve!'')
• Light bulb, to a toon
• 'No ___' ('Beats me')
• Invention impetus
• "The very" thing
• Key element
• 'What's the big ___?'
• It may be preconceived
• Gray matter matter?
• It may be bright
• Coconut yield?
• Opera's hero, often