Oval
Part of speech: noun
Definition: A shape rather like an egg or an ellipse. A sporting arena etc. of this shape.
Part of speech: adjective
Definition: Having the shape of an oval.
Example sentence: We had thousands of people outside Queen's Park Oval in Trinidad. We would wait to get inside to watch a Test at six o'clock in the morning.
Ellipse
Part of speech: noun
Definition: A closed curve, the locus of a point such that the sum of the distances from that point to two other fixed points (called the foci of the ellipse) is constant; equivalently, the conic section that is the intersection of a cone with a plane that does not intersect the base of the cone.
Part of speech: verb
Definition: To remove from a phrase a word which is grammatically needed, but which is clearly understood without having to be stated.