Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Galician
custar
←
Latin
constāre
(inherited)
←
Latin
constō
(mention)
←
Old Portuguese
custar
(inherited)
←
Old Portuguese
costar
(mention)
→
Galician
custa
(back-formation)
→
Galician
custa
(link)
→
Galician
custas
(back-formation)
→
Galician
custas
(link)