Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
muc
←
Breton
moc’h
(cognate)
←
Proto-Celtic
*mokkus
(inherited)
←
Welsh
moch
(cognate)
←
Cornish
mogh
(cognate)
←
Old Irish
mucc
(inherited)
→
Irish
muiceoil
(affix)
→
Irish
muicí
(affix)
→
Irish
mucár
(affix)