Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Church Slavonic
мꙑ
←
Proto-Slavic
*my
(inherited)
→
Lithuanian
mes
(cognate)
→
Russian
мы
(cognate)