Source : Webster's Revised Unabridged Dictionary (1913)

Oogonium \O`["o]*go"ni*um\, n.; pl. L. {O["o]gonia}, E.
   {O["o]goniums}. [NL., fr. Gr. w,'o`n an egg + ? offspring.]
   (Bot.)
   A special cell in certain cryptogamous plants containing
   o["o]spheres, as in the rockweeds ({Fucus}), and the orders
   {Vaucherie[ae]} and {Peronospore[ae]}.