Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Irish
tussu
←
Old Irish
tú
(affix)
←
Old Irish
-su
(affix)
→
Irish
tusa
(inherited)
→
Scottish Gaelic
thusa
(inherited)
→
Manx
uss
(inherited)