CROSSBONES n.
A representation of two of the leg bones or arm bones of a skeleton, laid crosswise, often surmounted with a skull, and serving as a symbol of death. Crossbones, scythes, hourglasses, and other lugubrios emblems of mortality. Hawthorne.
CRUS n.
Often applied, especially in the plural, to parts which are supposed to resemble a pair of legs; as, the crura of the diaphragm, a pair of muscles attached to it; crura cerebri, two bundles of nerve fibers in the base of the brain, connecting the medulla and the forebrain.