Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Celtic
*tantā
→
Welsh
tant
(inherited)
→
Irish
téad
(inherited)
→
Icelandic
þenja
(cognate)
→
Old Irish
tét
(inherited)