noun
reliquary
A container for holy relics, used in Christian contexts. The term 'feretrum' is a less common synonym.
教会の聖骨箱には聖人の遺骨が納められている。
The church's reliquary contains the bones of a saint.
Compound of 聖 (sei, 'holy'), 骨 (kotsu, 'bone'), and 箱 (hako, 'box'). The reading せいこつばこ follows standard on'yomi for the first two characters and kun'yomi for the last, with rendaku voicing on 箱.