myelencephalon
noun
my·e·len·ceph·a·lon ˌmī-ə-len-ˈse-fə-ˌlän 
-lən-
: the posterior part of the developing vertebrate hindbrain or the corresponding part of the adult brain composed of the medulla oblongata
myelencephalic
ˌmī-ə-ˌlen(t)-sə-ˈfa-lik
adjective 
Word History
Etymology
earlier, as a name for the cerebrospinal axis of vertebrates, from myel- + encephalon, perhaps after French myélencéphale
First Known Use
1871, in the meaning defined above
Medical Definition
myelencephalon
noun
my·el·en·ceph·a·lon ˌmī-ə-len-ˈsef-ə-ˌlän, -lən
: the posterior part of the developing vertebrate hindbrain or the corresponding part of the adult brain composed of the medulla oblongata