defensive balloon

Meaning

A large, tethered balloon filled with gas, typically hydrogen or helium, used as a passive aerial defense measure to deter or obstruct enemy aircraft, especially during wartime. These balloons often carried steel cables to damage aircraft that collided with them.

Examples

• During World War II, many cities deployed a defensive balloon barrage to protect against bomber raids.
• The engineers worked to improve the design of the defensive balloon, making it more resistant to strong winds.