Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Middle Irish
fer
←
Proto-Indo-European
*wiHrós
(inherited)
←
Primitive Irish
*ᚃᚔᚏᚐᚄ
(inherited)
←
Old Irish
fer
(inherited)