GNU Collaborative International Dictionary of English

Found one definition

1.       
   ‖Ovum , n.; pl. L. Ova , E. Ovums . [L., an egg. See Oval.]
   (Biol.) A more or less spherical and transparent cell, which by a process of multiplication and growth develops into a mass of cells, constituting a new individual like the parent; an egg, spore, germ, or germ cell. See Illust. of Mycropyle.
   1913 Webster
   ☞ The ovum is a typical cell, with a cell wall, cell substance, nucleus, and nucleolus. In man and the higher animals the cell wall, a vertically striated membrane, is called the zona pellucida; the cell contents, the vitellus; the nucleus, the germinal vesicle; and the nucleolus, the germinal spot. The diameter of the ripe ovum in man and the domestic animals varies between 1-200 and 1-120 of an inch.
   1913 Webster
   (Arch.) One of the series of egg-shaped ornaments into which the ovolo is often carved.
   Gwilt.
   
   1913 Webster