The names Ireland and Éire both come from the Old Irish word Ériu. This word is based on the Proto-Celtic word ɸīweriyū, which means "fertile soil." The ancient Latin name for the island of Ireland, Ivernia, also comes from this same root. Ivernia is still used today as a poetic name for the island, though it is often spelled "Hibernia" because of the Latin word "hibernum," which means "winter."