Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Polish
pęk
←
Proto-Slavic
*pǫkъ
(inherited)
→
Polish
Pęk
(mention)
→
Polish
Penk
(mention)
→
Polish
Pęksa
(mention)
→
Polish
pęczek
(suffix)