'archencephalon' originates from Greek, specifically the elements 'archē' and 'enkephalos', where 'archē' meant 'beginning, principal' and 'enkephalos' meant 'in the head (brain)'.

'archencephalon' was formed from Greek elements (arkhē + enkephalon) and entered scientific/Neo-Latin usage in anatomy; it later appeared in English anatomical literature but was gradually supplanted by more precise terms such as 'rhinencephalon' and parts of the telencephalon.

Initially it referred broadly to the primitive or olfactory portion of the brain; over time the term's use narrowed and largely fell out of modern anatomical terminology, replaced by more specific names.