Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Catalan
beç
←
Proto-Celtic
*betwiyos
(derived)
←
Occitan
beç
(cognate)
←
Middle Welsh
bedw
(cognate)
→
Occitan
beç
(cognate)