The Collaborative International Dictionary
myelencephal
Myelencephalon \My`e*len*ceph"a*lon\, n. [NL., from Gr. myelo`s marrow + E. encephalon.] (Anat.)
The brain and spinal cord; the cerebro-spinal axis. Sometimes abbreviated to myelencephal.
The metencephalon.
--Huxley.