2. n. [Drilling]
The open location on a mast-type rig (nonderrick) that functions like the vee-door. At least two sides are open on most mast rigs. Hence, the open side adjacent to the slide and catwalk is considered the vee-door. The vee-door is really a hole and has no true door that can be closed or locked, so inexperienced visitors to a rigsite are sometimes asked by the rig crew to find the key to the vee-door as a joke.
See: mast