primordial ovum

noun

: one of the large cells in the germinal epithelium and in the sexual cords or egg tubes derived from it which occur in embryos of both sexes but more abundantly in the female and from which the true eggs are believed to be derived

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now