Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
North Frisian
bök
←
Proto-West Germanic
*bōk
(derived)
←
Old Frisian
bōk
(derived)
→
North Frisian
buk
(cognate)