Turnstile
Pronunciation : Turn"stile`
Part of Speech : n.
Definition : 1. A revolving frame in a footpath, preventing the passage of horses or cattle, but admitting that of persons; a turnpike. See Turnpike, n., 1.
2. A similar arrangement for registering the number of persons passing through a gateway, doorway, or the like.
Source : Webster's Unabridged Dictionary, 1913