- a post with revolving horizontal bars, placed in an entrance to allow the passage of persons but not of horses, cattle, etc.
- a similar apparatus, often coin-operated, used to admit persons one at a time
- A gate having projecting bars that can be rotated to allow one person at a time to pass through, often having a mechanism to allow passage only in one direction or to require payment, as by means of a token.
- A gate controlling access to a space by another mechanical or electronic means, as by panels that slide out of the way when a card is swiped.
- A rotating mechanical device that controls and counts passage between public areas, especially one that only allows passage after a charge has been made.
- (mathematics, logic, proof theory) The symbol used to represent logical entailment (deducibility relation), especially of the syntactic type, i.e., syntactic consequence. (Such symbol can be read as "proves". )
- Comma-separated elements preceding the turnstile should be interpreted as forming a conjunction, whereas comma-separated elements following the turnstile should be interpreted as forming a disjunction.