1. noun /ˈpɑː.tɪˌzæn,ˌpɑː.təˈzæn,ˈpɑɹ.tɪ.zən,ˈpɑɹ.tə.zən/
while Xenophanes, the first of these partisans of the One (for Parmenides is said to have been his pupil), gave no clear statement,
b) A fervent, sometimes militant, supporter or proponent of a party, cause, faction, person, or idea.
2. adjective /ˈpɑː.tɪˌzæn,ˌpɑː.təˈzæn,ˈpɑɹ.tɪ.zən,ˈpɑɹ.tə.zən/
a) Adherent to a party or faction; especially, having the character of blind, passionate, or unreasonable adherence to a party; as, blinded by partisan zeal.
b) Devoted to or biased in support of a party, group, or cause: partisan politics.
Wikipedia foundation.