Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
feadh
←
Irish
feá
(doublet)
←
Middle Irish
fed
(inherited)
←
Old Irish
ed
(inherited)
→
Irish
feá
(doublet)
→
Irish
feá
(alter)