Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
North Frisian
dör
←
North Frisian
döör
(mention)
←
West Frisian
doar
(mention)
←
Old Frisian
dore
(derived)
→
North Frisian
döör
(mention)