vitellarium
noun
vi·tel·lar·i·um
| \ ˌvīt-ᵊl-ˈar-ē-əm
\
\
plural vitellaria\ -ē-ə
\
\
Medical Definition of vitellarium
: a modified part of the ovary that in many flatworms and rotifers produces yolk-filled cells serving to nourish the true eggs