Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Catalan
rústic
←
Catalan
rústec
(doublet)
←
Latin
rūsticus
(borrowed)
→
Catalan
rústec
(doublet)