The internet gives various origins to this surname. According to the Internet Surname Database, the surname Cass, Casse and in Dublin Cash is a group of surnames which derive from the female personal name Cass – a short form of Cassandra which was introduced into Britain around the time of the Crusades This was the name of an ill-fated Trojan prophetess of classical legend, who was condemned to foretell the future but never to be believed The name is also a metronymic in northern England and Scotland, which is so say that it derives from the mothers name, rather than the fathers.
The website Forbears also gives the same definition and that it is the 23,900th most common surname in the world and there are approximately 21,503 people who bear this surname. The surname is most prevalent in the United States and the highest density is England .
The origins of the surname according to Arthur, William in his book “An Etymological Dictionary of Family and Christian Names” published in 1857, the origin is “Gaelic.) Cas, a verb, to turn against, to thwart, oppose; a difficulty, a trying situation, a cause. Cas, a castle, the primary sense is to separate, drive off, or hate; the radical sense of hatred is driving off.”
According to Edward MacLysaght in his book Surnames of Ireland, the name Cash appears frequently in medieval Dublin records as Cass and Casse, and is still found in small numbers in the country between Tipperary and Wexford.
According to the 1881 UK census, there were approx 2,300 individuals named Cass, with a high density in Yorkshire.