Oosporangium \O`o*spo*ran"gi*um\, n.; pl. L. {Oosporangia}, E. {Oosporangiums}. [NL., fr. Gr. w,'o`n an egg + ? vessel.] (Bot.) An oogonium; also, a case containing oval or rounded spores of some other kind than oospores. [1913 Webster]