Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Occitan
cel
←
Latin
caelum
(inherited)
→
Catalan
cel
(inherited)
→
Occitan
cèl
(inherited)
→
Old Portuguese
ceo
(cognate)