Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Irish
én
←
Proto-Celtic
*ɸetnos
(inherited)
→
Old English
feþer
(cognate)
→
Irish
éan
(inherited)
→
Irish
éanlaith
(derived)
→
Scottish Gaelic
eun
(inherited)
→
Manx
eean
(inherited)