This is the 9496th most frequent Polish word.
wielkanocny
Easter-related.
Here 'wielkanocnego' is an adjective describing the associated breakfast, indicating its connection to Easter.
Podczas wielkanocnego śniadania jemy jajka i żurek.
During the Easter breakfast, we eat eggs and sour rye soup.
In this case, 'wielkanocna' modifies 'dekoracja', showing that the decoration pertains to Easter.
Wielkanocna dekoracja stołu była śliczna.
The Easter table decoration was beautiful.
Here 'wielkanocnych' serves as an adjective describing the eggs, indicating that they are associated with Easter celebrations.