barn door

Short definition from Wiktionary

Noun

1. 1
   The large door of a barn.
2. 2
   Something large enough that a miss ought to be impossible.
3. 3
   A player who blocks every ball.
4. 4
   The groin area of a pair of pants, especially in reference to a fly.
5. 5
   An off-balance pivot on two points of contact.
6. 6
   Alternative form of barn door.

Verb

1. 1
   To apply or adjust the barn doors as part of lighting.