This is the 14147th most frequent Russian word.
оппозиционная
Oppositional.
Here, "оппозиционная" describes the party, indicating its stance as opposing the ruling or mainstream political group.
Оппозиционная партия предложила новую реформу.
The opposition party proposed a new reform.
In this sentence, "оппозиционная" modifies "позиция" and emphasizes opposition.
Ее оппозиционная позиция по данному вопросу вызвала бурные дебаты.
Her oppositional stance on the issue sparked heated debates.
Here, "оппозиционная" is used in the plural form to describe "articles" that promote ideas against a prevailing view or policy.