Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
clo
←
Proto-Brythonic
*klọw
(inherited)
←
Proto-Celtic
*klāwos
(inherited)
←
Proto-Indo-European
*(s)kleh₂w-
(derived)
←
Latin
clāvis
(cognate)
→
Welsh
cloi
(affix)
→
Irish
cló
(cognate)
→
Scottish Gaelic
clò
(cognate)