Thalamencephalon \Thal`a*men*ceph"a*lon\, n. [NL. See
{Thalamus}, and {Encephalon}.] (Anat.)
The segment of the brain next in front of the midbrain,
including the thalami, pineal gland, and pituitary body; the
diencephalon; the interbrain.
[1913 Webster]