nail

nail 1 A piece of metal that is used to hold two or more pieces of bone together (for example, after a fracture). 2 The horny plate on the end of the finger (fingernail) or toe (toenail). Each nail has a body, lateral nail folds on its sides, a lunula (the little moon-shaped feature at the base), and a proximal skin fold at its base. See also fingernail; nail care; toenail.