A visual exploration of words that look the same, sound the same, or are otherwise easily confused. Updated weakly, on Sundaes, through 2016.
I had a notion, but just double-checked my references to confirm it before answering. Merriam-Webster Collegiate doesn't make a distinction, but the one I'm familiar with is more in line with Oxford's New American Dictionary. Oxford says "Grecian" refers to ancient Greece, especially architecture of the period. So there's the Grecian schools of thought, the Grecian city-states, or the Grecian styles of architecture."Greek" appears to encompass Grecian, but also applies to preclassical and postclassical Greece, both in geography and culture.Things get much murkier in the Merriam-Webster Third International Unabridged for "grecian". (And yes, it is not a capitalized term there.) As a noun, first sense states it's a flat out synonym for Greek. Second sense (archaic) is that it's a specialist in study of Greek language and literature. Third sense is "a student in a sixth form of a school, as Christ's Hospital, London."Third International as an adjective is in the first sense the meaning you'd expect: "of or relating to Greece." The second sense is "of a woman's gown" and is "having flowing lines, layered pleats, and many soft folds."So apparently it's much more involved than I ever knew. But I do think of grecian urns, grecian poets and philosophers being those of the ancient civilization, and grecian temples which always face east. (As opposed to Roman and subsequent temples which face any old direction.)Sounds like a bar bet to me.
Sorry about the length of that. I have an ex sister-in-law who summed it up pretty well one day. "Geez. Ask him what time it is and you learn how to make a watch."