The word "radesyge" is a rare and archaic term with an ambiguous origin. Its spelling may seem confusing at first glance, but it can be broken down into its phonetic components. The IPA phonetic transcription for "radesyge" would be /ˈræd.sə.sədʒi/. The first syllable "rad" is pronounced like "radar" and the next two syllables "se" and "yge" are pronounced with the "s" sound followed by a soft "g" sound. The word is not commonly used and its meaning is unclear.
A chronic ulcerative disease of uncertain nature, probably either syphilis or leprosy, which prevailed in Norway and Sweden in the 18th century.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.