barn door

/B AA1 R N D AO1 R/
noun
  1. 1

    The large door of a barn.

  2. 2

    Something large enough that a miss ought to be impossible.

    โ€œBuying a barn door won't help your tennis game.โ€

  3. 3

    A player who blocks every ball.

  4. 4

    The groin area of a pair of pants.

    โ€œSomebody forgot to close his barn door again!โ€

  5. 5

    An off-balance pivot on two points of contact.

Source: https://en.wiktionary.org/wiki/barn%20door