Related Clues:

• Brain product
• Glimmering
• Think tank nugget
• Embryo of an invention
• It's in your head
• Clever thought
• Mind matter
• Creative spark
• Just a thought
• Plan of action
• Lightbulb, in toons
• Light bulb for Wile E. Coyote?
• Novel thought
• Lightbulb, in comics
• Hit on the head