Webster's Revised Unabridged Dictionary · 1913

Oospore

Oospore , noun

[Greek w,'o`n an egg + {not transcribed} a seed.]

(a)
(Botany) A special kind of spore resulting from the fertilization of an oosphere by antherozoids.
(b)
(Botany) A fertilized oosphere in the ovule of a flowering plant.