Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
-iedydd
←
Welsh
-iad
(compound)
←
Welsh
-ydd
(compound)
→
Welsh
-iedyddion
(compound)
→
Welsh
-edyddion
(compound)