Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Polish
ku
←
Proto-Indo-European
*kom
(inherited)
←
Proto-Slavic
*kъ(n)
(inherited)
←
Old Polish
k
(inherited)