Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
leth
←
Proto-Brythonic
*llaɨθ
(inherited)
←
Latin
lac
(derived)
→
Breton
laezh
(cognate)