ostensorio

An ostensorio, or ostensorium, is a liturgical vessel used in Catholic and some other Christian contexts to display the consecrated host for Eucharistic adoration outside the tabernacle. It is designed to publicly expose the Blessed Sacrament, typically during periods of devotion or processions such as Corpus Christi.

The term derives from Latin ostensorium, meaning a device used to show or display. In English, the vessel is often called a monstrance, with ostensorio sometimes used as well; in practice, many traditions use the terms interchangeably to refer to the same object, although some distinguish the monstrance as the vessel and the ostensorio as the broader display instrument.

Design and function commonly feature a precious-metal body—frequently gold or silver—ornamented with decorative motifs. A transparent window or chamber, often made of glass or crystal, houses the consecrated host and allows it to be viewed. The central area may be surrounded by a sunburst or radiating rays motif. A stand or support elevates the display for processions or public exposition, and the entire piece may be carried on a staff or carried by clergy during liturgical ceremonies.

Usage involves exposing the host for adoration by the faithful, either in chapels or churches, and during solemn processions. Exposition typically occurs under the supervision of a priest or deacon and may require ecclesiastical authorization. The ostensorio thus serves as a focal point for reverence, prayer, and liturgical celebration of the Eucharist.

History and regional practice vary, but ostensoria have been prominent in medieval and modern Catholic ritual, evolving in style from simple metal frames to highly ornate ceremonial objects.