This is the 3392nd most frequent Swedish word.
baltiska
Baltiska: "Baltic" (adjective related to the Baltic region or languages).
In this sentence, 'baltiska' is an adjective describing the noun 'länderna', meaning 'countries', to specify that they pertain to the Baltic region.
De baltiska länderna är Estland, Lettland och Litauen.
The Baltic countries are Estonia, Latvia, and Lithuania.
Here, 'baltiska' modifies 'kulturen', meaning 'culture', used attributively to indicate its relation to the Baltic area.
Den baltiska kulturen har rika traditioner och historia.
The Baltic culture has rich traditions and history.
In this context, 'baltiska' serves as an adjective qualifying 'språk', meaning 'languages', thus referring to the languages spoken in the Baltic region.