This is the 2304th most frequent Polish word.
unijnego
"Unijnego" means "of the Union" or "pertaining to the Union," typically referring to the European Union.
The word 'unijnego' refers to something belonging to or associated with the 'Unia', the Union.
Polska jest członkiem unijnego rynku.
Poland is a member of the Union's market.
Here, 'unijnego' describes 'prawa', indicating that the law is specific to the Union.
Regulacje unijnego prawa wymagają przestrzegania tych norm.
Regulations of Union law require compliance with these standards.
In this sentence, 'unijnego' modifies 'rozwoju', specifying that the economic development is relevant to the Union.