letter of marque

WordReference Random House Unabridged Dictionary of American English © 2026

let′ter of marque′, 

1. license or commission granted by a state to a private citizen to capture and confiscate the merchant ships of another nation.

Also, let′ters of marque′. Also called let′ter of marque′ and repris′al, let′ters of marque′ and repris′al. 

• late Middle English 1400–50

Collins Concise English Dictionary © HarperCollins Publishers::

letter of marque, letters of marque noun

1. a licence granted by a state to a private citizen to arm a ship and seize merchant vessels of another nation
2. a similar licence issued by a nation allowing a private citizen to seize goods or citizens of another nation

Also called: letter of marque and reprisal