partisan (partisans plural )
1 adj Someone who is partisan strongly supports a particular person or cause, often without thinking carefully about the matter.
He is clearly too partisan to be a referee.
2 n-count Partisans are ordinary people, rather than soldiers, who join together to fight enemy soldiers who are occupying their country. He was rescued by some Italian partisans.
non-partisan
in AM, use nonpartisan
A person or group that is non-partisan does not support or help a particular political party or group. adj
(=neutral)
...a non-partisan organization that does economic research for business and labor groups.