With the advent on November 1 of Día de los Muertos, Day of the Dead, people in Mexico and neighboring American states like Texas have been seeing celebratory, stylized images of calaveras, or ‘skulls.’ The Spanish word developed from a presumed *calvera, which would have been the natural development of Latin calvaria ‘human skull.’ English speakers recognize that as the source (via French calvaire) of Calvary, the name given to the hill outside ancient Jerusalem where Jesus was crucified.
Joan Corominas notes that Spanish speakers partially confused the old *calvera with cadáver, which accounts for the extra a in the modern form calavera. And speaking of mixups, I can attest that some Catholic children in the New York of the 1950s confused Calvary with the cavalry that they were used to seeing on the movie screens and televisions of the era.
Latin calvaria, which was a translation of the original Aramaic gulgulta ‘skull,’ came from calvus ‘bald,’ based on the notion that a human skull has lost all its hair (and skin and muscle) and is effectively bald. We recognize calvus as the source of the synonymous Spanish calvo.
© 2011 Steven Schwartzman