Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Middle French
doncques
←
Old French
donkes
(inherited)
←
Latin
ad
(inherited)
←
Latin
tunc
(mention)
→
French
donc
(mention)