Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Celtic
*trummos
→
Welsh
trwm
(inherited)
→
Irish
trom
(inherited)
→
Scottish Gaelic
trom
(inherited)
→
Galician
trosma
(derived)
→
Manx
trome
(inherited)
→
Old Irish
trom
(inherited)