The term 'KIND OF DOCTOR' can be summarized by two crossword solutions: SPIN (4 letters) and EYE (3 letters). SPIN stands for Sports Physician and Injury Network, which is a network of doctors who specialize in sports medicine. They diagnose and treat injuries related to physical activity, such as sprains, fractures, and concussions. EYE stands for Ophthalmologist, which is a doctor who specializes in the diagnosis and treatment of EYE diseases and disorders. They can also perform surgery on the eyes, such as cataract removal.