noun
side door; side gate; small door within a larger gate
Refers to a small door or wicket gate set into a larger gate or wall, often used for pedestrian access. Common in traditional Japanese architecture.
大きな門の横に潜り戸がついている。
There is a small side door next to the large gate.
夜遅くに帰ったので、潜り戸から入った。
I came home late at night, so I entered through the wicket gate.
Compound of 潜り (くぐり, 'passing through', from verb 潜る くぐる) and 戸 (と, 'door'). The reading くぐりど is a rendaku form of と.