Nāil1, n.
n. [A-S. nāgel, O. Sax. & O. H. Ger. nagal, Icel. nagli, nōgl, Sw., D., & N. H. Ger. nagel, Dan. nagle, nōgl, Goth. nagls, O. Fries. neil, allied to Skr. nakha, nakhara. Russ. nógot, Lith. nagas, Gr. ὄ-νυξ, gen. ὄ-νυχος, Lat. unguis.]
Sense 1. The horny scale growing at the end of the human fingers and toes; a special form of epidermis, and homologous with the hoofs and claws of lower animals.
Sense 2. The claw or talon of a bird or other animal.
Sense 3. A small, pointed piece of metal, usually with a head, to be driven into a board or other piece of timber, and serving to fasten it to other timber, or left projecting, as from a wall, to hang any thing upon.
☞ The different sorts of nails are named either from the use to which they are applied, or from their shape, as shingle, floor, ship-carpenters', and horse-shoe nails, rose-heads, diamonds, &c. “The term penny, when used to mark the price of nails, is supposed to be a corruption of pound. Thus, a four-penny nail was such that one thousand of them weighed four pounds, ten-penny such that one thousand weighed ten pounds, &c.” New Amer. Cyc.
Sense 4. A measure of length, being two inches and a quarter, or the sixteenth of a yard.
On the nail, in hand; immediately; without delay or time of credit; as, to pay money on the nail. — To hit the nail on the head, to hit or touch the exact point.