halogen (n.)

general name for elements of the chlorine family, 1842, from Swedish, coined by Swedish chemist Baron Jöns Jakob Berzelius (1779-1848), literally "salt-producer," from Greek hals "salt" (from PIE root *sal- "salt") + -gen "giving birth to" (see -gen); so called because a salt is formed in reactions involving these four elements. Related: Halogenous.