Related Clues:

• It can come to a head
• Start of a brilliant scheme
• Problem solver, perhaps
• Cortex product
• Brainy thoughts
• "What's the big __?"
• Reason to shout 'Eureka!'
• Asset for an inventor
• You might bounce it off someone
• Hunch
• Innovative thought
• Creative notion
• It pops into the head
• Invention seed
• Patent seed