a slender, typically rod-shaped rigid piece of metal, usually in any of numerous standard lengths from a fraction of an inch to several inches and having one end pointed and the other enlarged and flattened, for hammering into or through wood, other building materials, etc., as used in building, in fastening, or in holding separate pieces together.
a thin, horny plate, consisting of modified epidermis, growing on the upper side of the end of a finger or toe.
a former measure of length for cloth, equal to 2¼ inches (6.4 cm).
to fasten with a nail or nails: to nail the cover on a box.
to enclose or confine (something) by nailing (often followed by up): to nail up oranges in a crate.