Definition of closer in US English:

closer

noun

  • 1The last part of a performance, collection, or series.

    ‘the perfect closer to the album’
    ‘the last episode was still a great closer’
  • 2A person who is skilled at bringing a business transaction to a satisfactory conclusion.

    ‘this role will best suit closers who are hungry to make commissions’
  • 3Baseball
    A reliable relief pitcher who enters a game in the final innings, typically to preserve a slim lead.

    ‘he could develop into a big-league closer’
    ‘one of the game's highest-paid closers’