Emily Dickinson Lexicon

PAR'TI-SAN, n. [s as z. Fr. from parti, partir.]

1. An adherent to a party or faction. – Addison.
2. In war, the commander of a party or detachment of troops, sent on a special enterprise; hence,
3. By way of distinction, a person able in commanding a party, or dextrous in obtaining intelligence, intercepting convoys or otherwise annoying an enemy.
4. A commander's leading staff. – Ainsworth.
5. A kind of halbert. [Fr. pertuisane; It. partigiano.]