Related Clues:

• "I've got an __!"
• Sudden urge
• Light bulb, in the comics
• It may be big
• Genesis of a plan
• Think tank matter
• ---
• Inventor's brainchild
• Mental creation
• Thought hidden in eight long puzzle answers
• Inventor's first step
• Start of a plan
• Bit of spontaneity
• A good one may come to mind
• Brain flash