Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
teithi
←
Proto-Celtic
*tanxtyos
(derived)
←
Welsh
teithio
(mention)
←
Old Irish
téchtae
(cognate)
→
Old Irish
téchtae
(cognate)