This is the 224th most frequent Croatian word.
zemalja
"Zemalja" means "of countries" or "of lands" (genitive plural form of "zemlja").
In this sentence, 'zemalja' is the genitive plural form of 'zemlja', used to indicate the idea of 'many countries'.
Posjetio sam mnogo zemalja tijekom svog života.
I have visited many countries during my life.
Here, 'zemalja' appears as part of a prepositional phrase in the genitive case, showing the location or association.
Raznolikost jezika u tim zemljama je fascinantna.
The diversity of languages in those countries is fascinating.
'Zemalja' in this sentence is used in its genitive plural form to link the possession of 'the map' to the countries.