Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
English
Lugh
←
Proto-Celtic
*Lugus
(derived)
←
Irish
Lugh
(borrowed)
←
Primitive Irish
ᚂᚒᚌ
(derived)
←
Old Irish
Lug
(derived)
→
English
Louth
(mention)