The story
- Proto-Indo-European · derived from*pélh₁us“many”
- Proto-Celtic · derived from*ɸelus“many”
- Latin · borrowed fromHelvetii
- English todayHelvetii
From Latin Helvetii, from a Celtic name. First element from Proto-Celtic *ɸelus (“many”), from Proto-Indo-European *pélh₁us (“many”); second element said to be from Celtic root *ɸeitu (“grassland, terrain”), which shares an origin with Old Irish íath (“grassland, territory”).
Etymology from Wiktionary, CC BY-SA 4.0.