Cartel /(?)/

Car·tel

Cartel

n.
  1. An agreement between belligerents for the exchange of prisoners. (Mil.)
  2. A letter of defiance or challenge; a challenge to single combat. [Obs.]
    He is cowed at the very idea of a cartel.,

Phrases & Compounds
Cartel
a ship employed in the exchange of prisoners, or in carrying propositions to an enemy; a ship beating a flag of truce and privileged from capture.

Cartel

v. t.
  1. To defy or challenge. [Obs.]
    You shall cartel him.