背戸 is read as せど (sedo) and means back door.
せど
sedo
せどのうまもあいくち
even an unruly horse can be tamed
うらせど
back door
せぼね
spine
せのび
standing on tiptoe and stretching one's back to make oneself taller
せなかをまるめる
to hunch one's shoulders
せがわ
back of a leatherbound book
しょいかわ
sling
はいけいがぞう
background image
せがひくい
short (of a person)
せのひくい
はいあつ
back pressure
せのじゅん
order of height