Webster’s Revised Unabridged Dictionary · 1913
Oöspore
O′ö·spore, n. [Gr. ᾠόν an egg + σπόρος a seed.] (Bot.) (a) A special kind of spore resulting from the fertilization of an oösphere by antherozoids. (b) A fertilized oösphere in the ovule of a flowering plant.