Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Irish
cach
←
Proto-Celtic
*kʷākʷos
(derived)
←
Welsh
pob
(cognate)
←
Old Irish
cách
(mention)
←
Middle Welsh
pawb
(cognate)
→
Irish
gach
(inherited)
→
Scottish Gaelic
gach
(inherited)
→
Manx
dagh
(inherited)
→
Middle Irish
cach
(inherited)