Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
aren
←
Proto-Celtic
*ārū
(inherited)
←
Latin
rēn
(cognate)
←
Old Irish
áru
(cognate)
←
Middle Welsh
arenn
(inherited)
←
Tocharian A
āriñc
(cognate)
→
Old Irish
áru
(cognate)