English
extraaxial
From extra- + axial.
Proto-Indo-European *h₁éǵʰs ‘out’
Proto-Indo-European *h₁eǵʰsteros
Proto-Italic *eksteros
Latin exter ‘being on the outside’
Latin extrā ‘outside, except, beyond’
English extra-
Today it means
adj Outside of the parenchyma (but still within the brain)
Language periods are conventional ranges, not dates for this word.
Etymograph / extraaxial