noun
1. a thin, horny plate, consisting of modified epidermis, growing on the upper side of the end of a finger or toe;
The police had been trying to nail those guys for months.
2. 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.
slang
3. to catch someone, especially when they are doing something wrong, or to make it clear that they are guilty;
The police had been trying to nail those guys for months.
phrasal verbs
4. to nail down - to catch someone, especially when they are doing something wrong, or to make it clear that they are guilty;
They're on the verge of getting the agreement nailed down.
5. to nail someone - to have sex with
Yes! I finally nailed Jane last night!
Examples: