Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Portuguese
con
←
Proto-Indo-European
*ḱóm
(inherited)
←
Latin
cum
(inherited)
→
Fala
con
(inherited)
→
Galician
con
(inherited)
→
Portuguese
com
(inherited)