Meaning

• An adherent to a party or faction.

• A fervent, sometimes militant, supporter or proponent of a party, cause, faction, person, or idea.

• A member of a band of detached light, irregular troops acting behind occupying enemy lines in the ways of harassment or sabotage; a guerrilla fighter.

• The commander of a body of detached light troops engaged in making forays and harassing an enemy.

Meaning

• Serving as commander or member of a body of detached light troops.

  "partisan officer, partisan corps"

• Adherent to a party or faction; especially, having the character of blind, passionate, or unreasonable adherence to a party.

  "They were blinded by partisan zeal."

• Devoted to or biased in support of a party, group, or cause.

  "partisan politics"