Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Occitan
blanc
←
Proto-Germanic
*blankaz
(derived)
←
Proto-Indo-European
*bʰleyǵ-
(root)
←
Proto-Indo-European
*bhleg-
(derived)
→
Catalan
blanc
(inherited)
→
Occitan
blanc
(inherited)