Why do we call Holy Communion a “host?” What does the word “host” mean here?
"Host” comes from the Latin word for “Victim” (hostia). There’s even a Latin Hymn about the Eucharist called “O Salutaris Hostia” which means “O Saving Victim.” Why would we use the word “victim” to describe Holy Communion? Because the Mass is a sacrifice.
Think of some of the other language we use at Mass: “May the Lord accept the sacrifice at your hands for the praise and the glory of his name….” Others words are new to us since the new translation of the Roman Missal, words like oblation, and phrases such as “these gifts, these offerings, these holy and unblemished sacrifices,” and “this pure victim, this holy victim, this spotless victim.”
Here’s how the Compendium of the Catechism of the Catholic Church explains it:
The Eucharist is the very sacrifice of the Body and Blood of the Lord Jesus which he instituted to perpetuate the sacrifice of the cross throughout the ages until his return in glory. Thus he entrusted to his Church this memorial of his death and Resurrection….
The Eucharist is a memorial in the sense that it makes present and actual the sacrifice which Christ offered to the Father on the cross, once and for all on behalf of mankind…. The sacrifice of the cross and the sacrifice of the Eucharist are one and the same sacrifice. The priest and the victim are the same; only the manner of offering is different: in a bloody manner on the cross, in an unbloody manner in the Eucharist.
So when we receive the “host,” we are receiving the victim of the Sacrifice of the Mass – Christ Himself who was sacrificed once for all on the cross for our salvation.