Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
amaideacht
←
Irish
amaid
(affix)
←
Irish
-acht
(affix)
←
Scottish Gaelic
amaideachd
(cognate)
←
Middle Irish
amaidecht
(inherited)
→
Irish
amaideach
(back-formation)
→
Scottish Gaelic
amaideachd
(cognate)