- A Roman Catholic Mass celebrated in full ceremonial form, in which the celebrant is assisted by a deacon and a subdeacon and accompanied by acolytes, a thurifer, and a choir.
- A Missa Cantata or sung Mass.
The term High Mass was common before the Second Vatican Council (1960s), when Masses were either "high" or "low". Since the Council, there are varying degrees of solemnity, so this term, along with "Low Mass", is falling out of use, except perhaps among Tridentine Catholics.
- “High Mass” in Dictionary.com Unabridged, v1.0.1, Lexico Publishing Group, 2006.