Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Russian
сего́дня
→
Belarusian
сёння
(cognate)
→
Belarusian
сягоння
(cognate)
→
Ukrainian
сьогодні
(cognate)