In historical documents, it is not uncommon to see photos or other references to someone or something given with an approximate date such as circa 1900. (Words most often found near circa are B.C., A.D., photo, and a variety of round dates.) It may also be used occasionally in approximate recollection: “Circa 1975, I read a lot of Shazam! comic books.” But many people circle around this word uncertainly, not sure how it should be used. You may see signs on restaurants or stores declaring them to be “circa 1985” or “circa 1997.” What’s that about?
Well, it seems they think that circa, in photos of buildings from a certain time, for instance, means not “about” or “around” but rather “established” or “founded.” So we have a bit of a semantic circus, as it were. But if circa – and circus, for that matter – makes you think of circle, then you’re at the origin: a Latin root referring to circles and roundness. Circa is taken directly from the Latin for “around” or “about.” And the two round c‘s can only reinforce that effect.
Those two c’s were both pronounced [k] in the original Latin, though in English they have the tongue do a half-circuit in the mouth, from tip through middle (the /r/) to back. Another word that closely resembles circa has a similar pronunciational history, but with the added detail that it came from Greek but was passed through Latin to give us the c rather than k spelling: Circe.
What’s Circe? Rather, who is Circe: a sorceress whose place Odysseus (or Ulysses, in the Roman version) hung around for a while. Her name is from the Greek kirké, “falcon” (but is now said like “Sir See”). When Odysseus’s men arrived, they found what seemed like a circus menagerie of docile animals. In fact, they were previous visitors, drugged and transmogrified. Many of Odysseus’s men were soon thus transmogrified, too, but Odysseus was warned, and when he went to free his men, he was met by Hermes (in his pre-fashion-designer days!), who gave him a herb which would protect him from the spells of Circe so he could bargain with her effectively (which he did; the movie version of that part would be rated R or X). What was the herb? It was the holy herb moly (Greek molu). So by eating holy moly, he was protected from being transformed.
Which reminds me of Shazam! Its protagonist had only to invoke the name of the wizard Shazam to be transformed into Captain Marvel (good newsstand competition for Superman). It happens that characters in the Shazam! comic books liked to exclaim “Holy moly!” I read these comic books circa 1975, as I have said, but I did not learn until circa 15 minutes ago what holy moly originally referred to, before it became an expletive. And so I am come full circa, as it were.