- a structure of four horizontally revolving arms pivoted atop a post and set in a gateway or opening in a fence to allow the controlled passage of people.
- a similar device set up in an entrance to bar passage until a charge is paid, to record the number of persons passing through, etc.
- a mechanical gate or barrier with metal arms that are turned to admit one person at a time, usually in one direction only
- any similar device that admits foot passengers but no large animals or vehicles
- a symbol of the form ̃⊢, ⊨, or ⊩, used to represent logical consequence when inserted between expressions to form a sequent, or when prefixed to a single expression to indicate its status as a theorem
