nail a lie
nail a lieBRITISH, JOURNALISM
If you nail a lie, you show that something is definitely not true. Top designer Calvin Klein is one of those helping to finally nail the lie that young is best.
nail a lieexpose something as a falsehood or deception.
The reference here is to shopkeepers nailing forged coins to their shop counter to expose them and put them out of circulation, or to farmers pinning dead vermin to a barn door as a deterrent to others.