A footstone is a marker at the foot of a grave. The footstone thus lies opposite the headstone, which is usually the primary grave marker. As indicated, these markers are usually stone, though modern footstones are often made of concrete, or some metal (usually bronze) in the form of a cast plate, which may or may not be set in concrete. The foots...
• (n.) The stone at the foot of a grave; -- opposed to headstone.
Foot'stone` noun The stone at the foot of a grave; -- opposed to headstone . 
a stone placed at the foot of a grave. · a kneeler at the foot of a gable.