Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Saterland Frisian
äärch
←
Proto-Germanic
*argaz
(inherited)
←
Old Frisian
erch
(inherited)
←
Old Frisian
erg
(mention)