Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Celtic
*kanxsman
→
Welsh
cam
(mention)
→
Irish
céim
(derived)
→
Manx
keim
(inherited)
→
Old Irish
céimm
(inherited)