Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
taves
←
Proto-Celtic
*tangʷāt-
(inherited)
←
Welsh
tafod
(cognate)
←
Proto-Indo-European
*dn̥ǵʰwéh₂s
(inherited)
←
Old Irish
tengae
(cognate)
→
Welsh
tafod
(cognate)