Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Slavic
*bělъkъ
→
Bulgarian
белтък
(inherited)
→
Czech
bílek
(derived)
→
Polish
białek
(inherited)
→
Old Polish
białek
(inherited)