Related Clues:

• Innovator's spark
• What a germ can become
• It may be just a hunch
• Inventor's basis
• What a light bulb may signify
• Mental conception
• Brainstorming contribution
• One may be lost in thought
• Overhead exclamation point, in comics
• "I had no ___!"
• Think-tank product
• "What's the big __ ?"
• "That's the general __"
• Clump up
• Something that comes to mind