What does brig mean?
A brig is a two-masted sailing ship in which both masts are rigged with square sails, a design prized in the seventeenth through nineteenth centuries for combining speed with maneuverability. Brigs served as merchantmen and warships alike, and the word survives today largely in historical and maritime contexts — in museums, novels of the age of sail, and accounts of naval history. The word also took on a second life in American military slang: because prisoners were once confined aboard such vessels, "the brig" came to mean a ship's jail and, more broadly, any military detention facility, as in "sentenced to thirty days in the brig." This figurative use remains common informally in the United States, especially in reference to the Navy and Marines. Compact and vivid, brig is a useful word for anyone reading maritime fiction, history, or military memoirs.
A two-masted sailing ship with both masts square-rigged.
"A fast brig could outrun most larger warships of its day."
Chiefly used in historical and maritime contexts today.
In US military slang, a place of confinement on board a warship, or a military detention facility generally.
"He spent the weekend in the brig."
Informal, chiefly American; common in Navy and Marine Corps usage.
Standard regular plural; applies to both the ship sense and the informal prison sense (though the latter usually appears as "the brig").
"Several brigs were anchored in the harbor."
"Thrown in the brig" comes straight from the name of a ship — sailors were locked up aboard vessels called brigs.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of brig
Brig originated as a colloquial shortening of "brigantine," a smaller two-masted sailing vessel, with the clipped form established by the early eighteenth century; it later settled specifically on the two-masted, square-rigged ship. Brigantine itself derives ultimately from the Italian brigantino, associated with brigante ("brigand"), reflecting the vessel's early association with pirates and rovers. The related term brigadier shares the same Romance root. The prison sense arose in American naval usage from confinement aboard these ships.
How brig is actually used
The nautical sense is standard English; the 'jail' sense is chiefly American, informal, and rooted in navy usage. The plural of brig is brigs.
Easily confused with brig
A bridge is a structure carrying a road or path over an obstacle (or the command area of a ship), while a brig is a type of sailing ship or a shipboard jail.
A brigand is a bandit or armed robber, whereas a brig is a two-masted sailing ship or a military prison.