Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
hesg
←
Breton
hesk
(cognate)
←
Irish
seisc
(cognate)
←
Proto-Indo-European
(inherited)
←
Cornish
hesk
(cognate)
→
Welsh
moresg
(compound)