réduit

Redoubt comes from French réduit, from Italian ridotto, meaning a place of refuge or retreat, from Latin reductus, past participle of redūcere (to lead back). The word means, at its root, 'the place you fall back to.' In military engineering, a redoubt was a temporary or permanent enclosed fortification, usually without flanking defenses — a square or polygonal position with walls and a ditch, designed as a final defensive point.

Redoubts were a standard feature of siege warfare from the Renaissance through the Napoleonic era. They were built into the siege lines by both attackers and defenders. The star fort — Vauban's great invention — incorporated redoubts as secondary positions within the main fortification. When the outer walls fell, the garrison retreated to the redoubt. It was the position of last resort.

The American Revolution's most famous defensive position was Breed's Hill — often misnamed Bunker Hill. The colonial militia built a redoubt overnight on June 16, 1775, and the next day held it against two British assaults before running out of ammunition. The redoubt on Breed's Hill was a crude earthwork thrown up in a few hours, but it worked exactly as a redoubt was supposed to: it gave defenders a concentrated position to hold.

The word survives in a figurative sense. A 'redoubt' is any stronghold of resistance: a conservative redoubt, a cultural redoubt, a democratic redoubt. The military meaning is nearly extinct — modern warfare does not use the term — but the metaphorical meaning thrives. The word for the last position to defend became the word for anything that refuses to yield.