noun
small gate; wicket gate
A small gate, often set into a larger gate or wall, through which people pass by ducking or bending. Typically found in traditional Japanese architecture, such as castle gates or temple entrances.
城門の脇に潜り門が設けられていた。
A small wicket gate was installed beside the castle gate.
夜間は大門を閉じ、潜り門だけを開けておいた。
At night they closed the main gate and left only the small gate open.
Compound of 潜り (くぐり, 'ducking' or 'passing under') + 門 (もん, 'gate'). The verb 潜る (くぐる) means to go under or pass through a low opening, reflecting the typical use of such a gate.