noun
    
    plural nails
    
    [count] a long, thin piece of metal that is sharp at one end and flat at the other end and that is used chiefly to attach things to wood
    
    
    
    the hard covering at the end of a finger or toe :a fingernail or toenail
    
    
    
    
    
    a nail in the/someone's coffin
    
    something that makes it more likely that someone or something will fail, be destroyed, etc.
    
    
    
    
    
    (as) hard/tough as nails
    
    of a person :very tough
    
    
    
    hit the nail on the head
    
    
    
    tooth and nail
    
    
    
    verb
    
    nails; nailed; nailing
    
    [+ obj] always followed by an adverb, adjective, or preposition :to attach (something) with a nail
    
    
    
    
    
    
    
    
    
    informal
    
    to catch (someone) doing something illegal or wrong
    
    
    
    to arrest or punish (someone) for doing something that is illegal or wrong
    
    
    
    
    
    informal :to hit (someone or something) forcefully
    
    
    
    US informal :to make or do (something) in a perfect or impressive way
    
    
    
    
    
    nail down
    
    [phrasal verb]
    
    nail (something) down or nail down (something)
    
    to make (something, such as a victory) certain to happen
    
    
    
    to find out or identify (something) exactly
    
    
    
    
    
    to make (something) definite or final