Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
eala
←
Breton
alarc'h
(cognate)
←
Proto-Celtic
*eli-
(derived)
←
Welsh
alarch
(cognate)
←
Ancient Greek
ἐλέα
(cognate)
←
Proto-Indo-European
*h₁el-
(derived)
←
Cornish
alargh
(cognate)
←
Latin
olor
(cognate)
←
Middle Irish
[[ela]], [[elae]]
(inherited)
←
Old Irish
elu
(inherited)
→
Welsh
alarch
(cognate)