I'm sorry for any confusion, but "Iceland" is a country located in Northern Europe, and it doesn't have a medical definition. If you're referring to a term in medicine that might be associated with Iceland, perhaps you're thinking of "Iceland syndrome," which is a medical condition named after the place where it was first described, not because it's unique to Iceland. It refers to a rare occurrence of unilateral lower limb edema (swelling) due to a deep vein thrombosis (blood clot) in the iliofemoral vein, often associated with malignancy.

Scandinavia, in a medical context, often refers to a geographical region consisting of Denmark, Norway, and Sweden, where shared cultural, linguistic, and historical ties can influence the delivery, organization, and research of healthcare systems.

The ash, dust, gases, and lava released by volcanic explosion. The gases are volatile matter composed principally of about 90% water vapor, and carbon dioxide, sulfur dioxide, hydrogen, carbon monoxide, and nitrogen. The ash or dust is pyroclastic ejecta and lava is molten extrusive material consisting mainly of magnesium silicate. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A group of nine islands and several islets belonging to Portugal in the north Atlantic Ocean off the coast of Portugal. The islands are named after the acores, the Portuguese for goshawks, living there in abundance. (Webster's New Geographical Dictionary, 1988, p102 & Room, Brewer's Dictionary of Names, 1992, p42)