A physical device, typically electronic, which computes a Boolean logical output (0 or 1) from Boolean input or inputs according to the rules of some logical operator.

An opening through which water may flow freely when the tide moves in one direction, but which closes automatically and prevents the water from flowing in the other direction.

a type of radial arm floodgate used in dams and canal locks to control water flow.

The process by which the brain adjusts its response to stimuli.

the amount of money made by selling tickets to a concert or a sports event

a Tainter gate

A small gate, used instead of a stile at the boundary of a field, that swings in a U- or V-shaped enclosure and touches (kisses) each of two gateposts, allowing one person at a time to pass through, but being too complex for livestock to operate.

A decommissioned aircraft, artillery piece, or tank, displayed near the entrance to an airport or military base.

The entrance to hell, seen as an embodiment of evil.

The gate at the back of a property, especially a residential property, often leading onto a lane.