Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Portuguese
lagoa
←
Proto-Indo-European
*lókus
(inherited)
←
Latin
lacūna
(inherited)
←
Latin
lacus
(mention)
←
Portuguese
lacuna
(doublet)
←
Old Portuguese
lagõa
(inherited)
→
Portuguese
lacuna
(doublet)
→
Portuguese
laguna
(doublet)
→
Portuguese
Lagoa
(mention)