Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Celtic
*wesrakos
→
Irish
earrach
(inherited)
→
Irish
arragh
(inherited(ga/gv))
→
Scottish Gaelic
earrach
(inherited)
→
Old Irish
errach
(inherited)