Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Middle Welsh
achaws
←
Proto-Brythonic
*axọs
(inherited)
←
Latin
occāsiō
(derived)
←
Old Irish
accuis
(cognate)
→
Welsh
achos
(inherited)
→
Old Irish
accuis
(cognate)