Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Ukrainian
серпень
←
Czech
srpen
(cognate)
←
Old East Slavic
серпьнъ
(inherited)
←
Polish
sierpień
(cognate)
←
Serbo-Croatian
srpanj
(cognate)