trip wire

The left leg is almost horizontal in the trip wire, and the right leg is bent.

Wire may be used as a high or low entanglement or as a fence or trip wire or concealed obstacle.

I then put the shells, one on either side, and connected them with a fine trip-wire tied to each ring.

He knelt down beside the menacing box of explosives and quickly disconnected the trip wire, throwing the box to one side.

If we'd hit a trip wire or something similar, the dynamite would have gone off right then.

This trip-wire was as difficult to cross as the wire of the entanglements.