“Sabaoth is one of those Hebrew words which were left untranslated in the earliest Latin version of the Holy Scriptures, called the Vetus Itala, and has been preserved in three places in the translation by St. Jerome. Sabaoth is a plural, and signifies ‘armies’. As the Roman Missal has always followed the ancient Italic version, [...]

This from Hierurgia: the Holy Sacrifice of the Mass, again, authored by Daniel Rock D.D.:
“The use of Images in the house of God, is authorized by Scripture. Moses was commanded to place the images of two Cherubim upon the Ark; and Solomon ‘carved all the walls of the Temple round about with divers figures and [...]

This is a term I discovered in my reading of the old book Hierurgia, which I mentioned before. It refers to the monstrance, the receptacle used for the Blessed Sacrament during Benediction.