What does "oval" mean?

Additional senses

1. 2.(Bot.) Broadly elliptical. Oval chuck (Mech.), a lathe chuck so constructed that work attached to it, and cut by the turning tool in the usual manner, becomes of an oval form.
2. 3.A body or figure in the shape of an egg, or popularly, of an ellipse. Cassinian oval (Geom.), the locus of a point the product of whose distances from two fixed points is constant; -- so called from Cassini, who first investigated the curve. Thus, in the diagram, if P moves so that P A.P B is constant, the point P describes a Cassinian oval. The locus may consist of a single closed line, as shown by the dotted line, or of two equal ovals about the points A and B.