Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Portuguese
cocegar
←
Latin
*cocicāre
(derived)
←
Latin
coquere
(mention)
←
Latin
coquō
(mention)
→
Portuguese
cócegas
(back-formation)