plural of zion

(mathematics) Any closed curve described by a Cartesian equation of the form (x²+y²)²=2a²(x²-y²).

Alternative letter-case form of go the way of the dodo

The cubical part of a pedestal; a plinth. / A device for cutting into a specified shape. / A device used to cut an external screw thread. (Internal screw threads are cut with a tap.)