The Collaborative International Dictionary of English v.0.48:

Oval \O"val\, n.
   A body or figure in the shape of an egg, or popularly, of an
   ellipse.
   [1913 Webster]

   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.
      [1913 Webster]
      [1913 Webster] Ovalbumin

The Collaborative International Dictionary of English v.0.48:

Oval \O"val\, a. [F. ovale, fr. L. ovum egg. Cf. Egg, Ovum.]
   1. Of or pertaining to eggs; done in the egg, or inception;
      as, oval conceptions. [Obs.]
      [1913 Webster]

   2. Having the figure of an egg; oblong and curvilinear, with
      one end broader than the other, or with both ends of about
      the same breadth; in popular usage, elliptical.
      [1913 Webster]

   3. (Bot.) Broadly elliptical.
      [1913 Webster]

   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.
      [1913 Webster]

WordNet (r) 3.0 (2006):

oval
    adj 1: rounded like an egg [syn: egg-shaped, elliptic,
           elliptical, oval, oval-shaped, ovate, oviform,
           ovoid, prolate]
    n 1: a closed plane curve resulting from the intersection of a
         circular cone and a plane cutting completely through it;
         "the sums of the distances from the foci to any point on an
         ellipse is constant" [syn: ellipse, oval]