The term sanguine is synonymous with “optimistic,” while sanguinary is associated with “involving a lot of bloodshed.” Surprisingly, these two words have a common origin rooted in the concept of bodily humors. In ancient times, it was believed that an excess of blood led to a cheerful temperament. Both words were borrowed from the Latin noun sanguinarius in the fourteenth century. This Latin term, meaning “of or pertaining to blood,” can be traced back to the Proto-Italic language, which is ultimately derived from the Proto-Indo-European reconstruction kreue, denoting blood outside the body. Interestingly, the PIE speakers made a distinction between blood inside and outside the body. In heraldry, the term sanguine can also refer to a type of blood-red tincture used in flags like that of Latvia.
