A circular or oval ring with an internal cutting edge used to shave off tumors in the nasal and other cavities.
The Hidden Histories Of “Humpty Dumpty,” “London Bridge,” And “Ring Around The Rosie”These hidden stories behind these three popular nursery rhymes may not be well known but they certainly make songs like "Humpty Dumpty" a little more interesting.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Examples from the Web for ring-knife
Removal through the nasal chambers—the route originally used by Meyer for his ring-knife—is not to be recommended.
With a ring-knife any irregular spicules or projections can be smoothed down.