Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Irish
sén
←
Latin
signum
(borrowed)
→
Irish
séan
(inherited)
→
Scottish Gaelic
seun
(inherited)
→
Old Irish
sénaid
(affix)