Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Scottish Gaelic
leagh
←
Proto-Celtic
*legāti
(inherited)
←
English
leak
(cognate)
←
Irish
leáigh
(cognate)
←
Manx
lheie
(cognate)
←
Proto-Indo-European
*leg-
(derived)
←
Old Irish
legaid
(inherited)
→
Irish
leáigh
(cognate)
→
Manx
lheie
(cognate)