Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-West Germanic
*-ārī
→
Old English
-ere
(inherited)
→
Bavarian
-er
(inherited)
→
Saterland Frisian
-er
(inherited)