Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
North Frisian
aatj
←
Proto-Germanic
*attô
(inherited)
←
Proto-Indo-European
*átta
(derived)
←
Old Frisian
*atta
(inherited)
→
English
dad
(mention)