Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Serbo-Croatian
тама
←
Bulgarian
тъма
(cognate)
←
Russian
тьма
(cognate)
←
Proto-Slavic
*tьma
(inherited)