oosporangium
/ˌəʊəspəˈran(d)ʒɪəm/(also oösporangium) Botany
noun
Originally: a unilocular sporangium of certain brown algae. Later: a megasporangium.
Origin
Mid 19th century; earliest use found in Miles Berkeley (1803–1889), Church of England clergyman and naturalist. From oo- + sporangium, after scientific Latin oosporangium (G. Thuret Ann. Sci. Nat (Bot.) 14 235, or earlier).