Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Church Slavonic
троудъ
←
Proto-Slavic
*trudъ
(inherited)
→
Old Church Slavonic
троудьнъ
(suffix)
→
Old Church Slavonic
троудьникъ
(suffix)