The Collaborative International Dictionary of English v.0.48:
Stomodaeum \Stom`o*dae"um\, n. [NL., from Gr. ?, ?, mouth + ? to divide.] 1. (Anat.) A part of the alimentary canal. See under Mesenteron. [1913 Webster] 2. (Zool.) The primitive mouth and esophagus of the embryo of annelids and arthropods. [1913 Webster]