blue-blood

Example: “The club's members are all blue-bloods from old New England families.”

Origin: A direct translation of the Spanish sangre azul, a phrase the old aristocratic families of Castile used of themselves. Those families prided themselves on lineage supposedly untouched by intermarriage with the Moors, Jews, or other groups who had lived on the Iberian peninsula, and pointed to their own pale skin, kept fair by staying indoors and out of manual labor, through which their veins showed a more visible blue than the skin of people who worked outdoors and tanned. That visible blue was taken as proof of "pure" ancestry, though it was simply a trick of complexion. The phrase entered English in the 1830s, with its earliest recorded appearance in George Borrow's 1843 book The Bible in Spain.