Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
llystad
←
Breton
leztad
(cognate)
←
Welsh
llys
(prefix)
←
Welsh
tad
(prefix)
→
Breton
leztad
(cognate)
→
Welsh
llystadau
(affix)