Barbwire (noun)

1. A type of fencing wire that has sharp points or barbs at regular intervals.
2. A barrier or obstacle made of this type of fencing wire.

Origin:

Blend of 'barb' and 'wire'. 'barb' refers to the pointed projection on a wire or fishhook, from old french 'barbe' meaning beard or pointed object. 'wire' comes from old english 'wir' meaning metal drawn out into a thin, flexible thread or rod.

Examples:

1. The farm was surrounded by barbwire fencing to keep the cattle from wandering off.
2. The prison was heavily guarded with barbwire fences and watchtowers.
3. The soldier was injured when he got caught on a barbwire fence during training.
4. The protesters were prevented from entering the government building by a wall of barbwire barricades.
5. The military base was protected by a perimeter of barbwire fencing and armed guards.