Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
gwych
←
Proto-Celtic
*weswos
(inherited)
→
Welsh
gwyched
(suffix)
→
Welsh
gwychach
(suffix)
→
Welsh
gwychaf
(suffix)