A wicket gate (sometimes 'wicket door' or 'pass door') is a small pedestrian gate built into the larger leaf of a driveway gate. The wicket is a separate hinged panel inside the main gate frame, with its own hinges, latch, and threshold. The most common pattern is a 900 mm wide wicket centred in one leaf of a double-swing gate or set off to one side of a sliding gate.
Wicket gates are common on commercial sites where cars and pedestrians use the same driveway entry. Opening the full gate every time someone walks in wastes time and (on automated gates) wastes a duty cycle.
Key design issue: where does the threshold live? A wicket cut from the gate frame leaves a steel threshold across the path that's a trip hazard. A wicket that opens to ground level needs a separate bottom rail it can latch into. Both options have downsides.