Related Clues:
- Lincoln is the only U.S. president to have one
- Apparent
- Clearly visible
- Inventor's legal document
- Gadget protector
- Kind of examiner 56-Across was
- Edison accomplishment, frequently
- Inventor's insurance
- Gadgeteer's acquisition
- My grandfather registered one for a voltage regulator circuit
- Invention protection
- Plainly evident
- It protects an invention
- The invention protection is obvious
- Perfectly plain and clear