Definition from Wiktionary, the free dictionary
turnstile (plural turnstiles)
- 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.
- (mathematics, logic): double turnstile
rotating mechanical device