Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Indo-European
*kuH-lo-
→
Welsh
cil
(inherited)
→
Irish
cúil
(inherited)
→
Scottish Gaelic
cùil
(inherited)