In science, a three-dimensional oval is formally called an ovoid. A less formal name for a three-dimensional oval shape is simply an egg. The word ovoid emerged in the early 19th century from the French "ovoïde," and Latin "ovoides," both referring to the egg.

An oval is a rounded shape that is slightly elongated, similar to that of an egg. The word is derived from the mid-16th century French word "ovalis" and the Latin word "ovum," both meaning egg. In geometry, for a figure to be called an ovoid, it must at least have one axis of symmetry, in addition to resembling an egg.