Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Celtic
*ɸrossos
→
Welsh
rhos
(inherited)
→
Irish
ros
(inherited)
→
Scottish Gaelic
ros
(inherited)
→
Cornish
ros
(inherited)
→
Old Irish
ros
(inherited)