means A soft, highly reactive silvery metal (element 11, symbol Na) that's essential to life as part of common salt and never found free in nature because it bonds with almost anything it touches.

from The English word comes from 'soda,' the old name for sodium-bearing compounds like washing soda, which traces back through medieval Latin and possibly Arabic 'suwwad,' a name for the saltwort plants whose ashes yielded it. Humphry Davy coined 'sodium' in the early 19th century after he first isolated the metal by electrolysis in 1807. The odd symbol 'Na' is a leftover from its Latin name 'natrium,' itself rooted in 'natron,' a naturally occurring salt the ancient Egyptians used to dry out mummies.