primary oocyte

https://doi.org/10.1351/goldbook.11041

Oocyte during growth phase before completion of the first meiotic division.

Note: The primary oocyte is diploid and becomes a secondary oocyte before birth.

Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 787 (https://doi.org/10.1515/pac-2015-1202)