boarding door; entrance (vehicle)
Refers to the door or entrance used for boarding a vehicle such as a bus, train, or taxi. Often contrasted with 降り口 (alighting exit).
See also: 降り口
バスの乗り口は前ですか、後ろですか。
Is the bus boarding door at the front or the back?
電車の乗り口で切符を確認された。
My ticket was checked at the train entrance.
horse mounting equipment
Only with reading のりくち
Archaic term for equipment used to restrain and mount horses. Reading restricted to のりくち.
古文書には「乗り口」を馬具の一種として記している。
Old documents record 乗り口 as a type of horse equipment.
Standard kanji spelling for the common reading のりぐち.
Irregular okurigana variant; less common and may be considered non-standard.
Compound of 乗り (boarding) + 口 (opening, entrance). The archaic horse-equipment sense is a specialized historical usage.