Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Church Slavonic
мѧкъкъ
←
Proto-Slavic
*mękъkъ
(inherited)
→
Latvian
mīksts
(cognate)