English
intrahelical
From intra- + helical.
Proto-Indo-European *h₁én ‘in’
Proto-Indo-European *h₁énteros ‘inside, within’
Latin *interus
Latin intrā ‘within’
English intra-
Today it means
adj Within a helix.
Language periods are conventional ranges, not dates for this word.
Etymograph / intrahelical