magnesium

Etymology

From New Latin magnēsium, from Ancient Greek μαγνησία (magnēsía), after Μαγνησία (Magnēsía, “Magnesia”), a region in Thessaly. Coined by British chemist Humphry Davy, as a modification of his original suggestion, magnium.

noun

1. The chemical element (symbol Mg) with an atomic number of 12. It is a light, easily flammable, silvery-white alkaline earth metal.
   1999, Chapter 1 "Barrens" Cryptonomicon by Neal Stephenson The building looked only like a wall glowing in the firelight, but sometimes a barrage of magnesium blue light made its windowframes jump out of the darkness.