Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Slavic
*jenъ
→
Czech
jen
(inherited)
→
Czech
jenom
(inherited)
→
Old Polish
jeno
(inherited)
→
Old Polish
jéno
(inherited)