What does "oosphere" mean?

A large nonmotile egg cell, especially of an alga or fungus, formed in an oogonium and ready for fertilization.

Oosphere

Common synonyms include: earlier usage, egg sphere, gamete sphere, historical usage, old term, oocyte sphere.

/ˈəʊəsfɪə/ noun

noun ·Rare ·Advanced level

Noun

1
A large nonmotile egg cell, especially of an alga or fungus, formed in an oogonium and ready for fertilization.
2
a gamete; used especially of lower plants wordnet

PIE word *h₂ōwyóm From oo- (prefix denoting something relating to eggs or ova) + -sphere, modelled after French oosphère.