C1 noun, adjective /ˈpɑːrtɪzən/
partisan
партийный сторонник
Meaning
A strong supporter of a party, cause, or person; showing biased allegiance.
Example
The debate quickly turned partisan, with each side defending their own agenda.
Дебаты быстро стали партийными, каждая сторона защищала свою повестку.