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 2 1 / 4 in. (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 fol. by up )

to nail up oranges in a crate.

to make fast or keep firmly in one place or position

Surprise nailed him to the spot.

to accomplish perfectly

the only gymnast to nail the dismount.

Informal .

to secure by prompt action; catch or seize

The police nailed him with the goods.

to catch (a person) in some difficulty, lie, etc.

to detect and expose (a lie, scandal, etc.).

Slang . to hit (a person)

He nailed him on the chin with an uppercut in the first round.

to focus intently on an object or subject

She kept her eyes nailed on the suspicious customer.

Obsolete . to stud with or as if with nails. ?

nail down, to make final; settle once and for all

Signing the contract will nail down our agreement.

hit the nail on the head

to say or do exactly the right thing; be accurate or correct

Your analysis really hit the nail on the head.

nail in someone's or something's coffin

something that hastens the demise or failure of a person or thing

Every moment's delay is another nail in his coffin.

on the nail

Informal .

of present interest; under discussion.

without delay; on the spot; at once

He was offered a job on the nail.

verb

unfasten , unnail , let go , liberate , release

verb

attach , beat , bind , drive , hammer , hit , hold , join , pin , pound , secure , sock * , spike , strike , tack , whack * , apprehend , bag , catch , collar * , detain , get * , hook * , nab , pinch * , prehend , seize , take * , capture , get , net , arrest , collar , detect , expose , trap