Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Slavic
*ȍko
→
Old Church Slavonic
око
(inherited)
→
Polabian
våťü
(inherited)
→
Silesian
ôko
(inherited)