noun
back cover; rear lid
Refers to the removable or openable back panel of a device such as a camera, watch, or remote control, often for battery or film access.
カメラの裏蓋を開けてフィルムを入れる。
Open the back cover of the camera and load the film.
時計の裏蓋を外して電池を交換した。
I removed the back cover of the watch and replaced the battery.
Compound of 裏 (ura, 'back') and 蓋 (futa, 'lid, cover'), with rendaku voicing of ふた to ぶた.