Webster's Revised Unabridged Dictionary · 1913

Oosphere

Oosphere (ō"o*sfēr) , noun

[Greek w,'o`n an egg + English sphere.]

1.
(Botany) An unfertilized, rounded mass of protoplasm, produced in an oogonium.

After being fertilized by the access of antherozoids it becomes covered with a cell wall and develops into an oospore, which may grow into a new plant like the parent.

2.
(Botany) An analogous mass of protoplasm in the ovule of a flowering plant; an embryonic vesicle. — Goodale