Par″ti‐san (pär″tĭ‐zan), n. [F., fr. It. partigiano. See Party, and cf. Partisan a truncheon.] [Written also partizan.] 1. An adherent to a party or faction; esp., one who is strongly and passionately devoted to a party or an interest. “The violence of a partisan.” Macaulay.
Both sides had their partisans in the colony. Jefferson.
2. (Mil.) (a) The commander of a body of detached light troops engaged in making forays and harassing an enemy. (b) Any member of such a corps.