from
The Collaborative International Dictionary of English v.0.48
Rhinencephalon \Rhi`nen*ceph"a*lon\
(r[imac]`n[e^]n*s[e^]f"[.a]*l[o^]n), n.; pl. {Rhinencephala}
(r[imac]`n[e^]n*s[e^]f"[.a]*l[.a]). [NL., fr. Gr. "ri`s,
"rino`s, the nose + 'egke`falos the brain.] (Anat.)
The division of the brain in front of the prosencephalon,
consisting of the two olfactory lobes from which the
olfactory nerves arise.
[1913 Webster]
Note: The term is sometimes used for one of the olfactory
lobes, the plural being used for the two taken
together.
[1913 Webster]