Definition of high masses:
(n) :
A Roman Catholic or Anglo-Catholic Mass celebrated in full ceremonial form, in which the celebrant is generally assisted by a deacon and, in the Tridentine form, a subdeacon, and accompanied by acolytes, a thurifer, and a choir.
(n) :
(loosely) Any sung Mass, including a Missa Cantata.
(n) :
Used other than figuratively or idiomatically: see high, mass.
(n) :
Alternative letter-case form of High Mass. [A Roman Catholic or Anglo-Catholic Mass celebrated in full ceremonial form, in which the celebrant is generally assisted by a deacon and, in the Tridentine form, a subdeacon, and accompanied by acolytes, a thurifer, and a choir.]