What is the meaning of Baldacchin?

A rich, embroidered brocade used for clothing in the Middle Ages, the web being gold and the woof silk.

A canopy suspended over an altar or throne, originally made of this fabric; a ciborium.

A building in the form of a canopy, or a crown supported by pillars for the covering of an altar; a canopy carried over the host in Roman Catholic countries.

Source: wiktionary.org