The word "claymore" has been used to describe two distinct types of swords used by Scottish warriors and soldiers. The first was a large, two-handed sword used in the medieval period. The second was a large basket-hilted sword and was issued to Scottish troops in the 18th century.
The M-18A1 Claymore Antipersonnel Mine
The design was originally conceived by the Germans during WW2 as an anti-tank mine firing a steel slab. It was never perfected although the discovery of the Misznay-Schardin effect led to the current device.
Following the massed Chinese attacks during the Korean War, the US Army developed the mine into a anti-personnel device that would fire hundreds of small ball-bearings in one go. Claymores were not buried like other mines but were placed above ground pointed towards the likely location of the enemy
Fully developed in time for the Vietnam War, as the M-18A1. The mine had an plastic olive casing with the words "Front Toward Enemy" on it. It was 21.5 cm long, 8 cm high, and 3.5 cm deep with two sets of little legs. Inside was 650 g of plastic explosive and 700 steel ball-bearings. When fired the contents sprayed out in a 60 degree arc that was lethal up to 50 metres. The mine could be either be fired on command using a hand held device or detonated by trip wire.
Claymores were often used in ambushes and to defend temporary positions.