Related Clues:
- Innovator's inspiration
- Invention starter
- Mental germ
- Basis of an invention
- Invention genesis
- What a light bulb sometimes signifies
- Inventor's springboard
- "The very ---!"
- Sneaking suspicion, e.g.
- Innovations' originations
- Think-tank products
- Starting point for an invention
- Head light bulb?
- Germs may lead to them
- Intangible spark