Meaning of “partisan” - Learner’s Dictionary

partisan

noun [ C ] uk us /ˌpɑːtɪˈzæn/ US  /ˈpɑːrtɪzən/
POLITICAL SUPPORTER
SOLDIER

a member of a group that secretly fights against soldiers who are controlling their country

(Definition of “partisan noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)