ostensorium
/ˌɒstɛnˈsɔːrɪəm/Roman Catholic Church
noun
An open or transparent receptacle used to display the Host to the congregation at mass; a monstrance.
Origin
Mid 18th century; earliest use found in John Adams. From post-classical Latin ostensorium monstrance from classical Latin ostens-, past participial stem of ostendere + -ōrium. Compare earlier ostensorio.