Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Westrobothnian
ér
←
Proto-Germanic
*arwaz
(inherited)
←
Old Norse
ęr
(inherited)
→
Westrobothnian
eru
(suffix)
→
Westrobothnian
räkstér
(suffix)
→
Westrobothnian
töttälér
(suffix)