superficies

Look below the surface of "superficies" and "surface" and you’ll find the very same Latin roots: "super-," meaning "on top," and "facies," meaning "face" or "aspect." English speakers plucked "superficies" right from Latin - it means "surface" in that language. Our word surface came to us by way of Middle French, where "sur-" (which comes from "super " and also means "on top") was combined with "face" (meaning "face"; from "facies"). We added "surface" to our crop of borrowed words around 1600, and the first known use of "superficies" is from 1530. One tricky thing to keep in mind about "superficies" is that it can be singular (even though it ends in an "s"!) or plural. There is no "superficie" or "superficy."