'Siphonium' definitions:
Definition of 'Siphonium'
- Siphonium \Si*pho"ni*um\, n.; pl. Siphonia. [NL., from Gr.
????, dim. of ????. See Siphon.] (Anat.)
A bony tube which, in some birds, connects the tympanium with
the air chambers of the articular piece of the mandible.
[1913 Webster]