Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
main
←
Breton
moan
(cognate)
←
Cornish
moon
(cognate)
→
Welsh
meinwe
(compound)
→
Welsh
meinwen
(compound)