Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Faroese
átta
←
Proto-Germanic
*ahtōu
(derived)
←
Proto-Indo-European
*oḱtṓw
(derived)
←
Old Norse
átta
(derived)
→
Faroese
áttamannafar
(compound)
→
Faroese
áttu
(mention)