What is the cut called for a dome shaped stone with only 1 facet (bottom)?

Question

I don't know what this cut is called. I just saw an amethyst ring that was just a smooth dome. It looked like a perfectly smooth sphere but cut in half with the flat part down and the smooth dome facing up. I looked up "dome cut" but that's a faceted dome, not a smooth one. I remember hearing it called a "cabochet" or something like that once, but I can't remember.

Answer 1

It's called a cabochon (also spelled cabachon).  See source.

Answer 2

/ cabochon