Introit
Pronunciation : In*tro"it
Part of Speech : n.
Etymology : [L. introitus, fr. introire to go into, to enter; intro within + ire to go: cf. F. introit.]
Definition : 1. A going in. Caxton.
2. (R. C. Ch.) (a) A psalm sung or chanted immediately before the collect, epistle, and gospel, and while the priest is entering within the rails of the altar. (b) A part of a psalm or other portion of Scripture read by the priest at Mass immediately after ascending to the altar.
3. (R. C. Ch.)
Defn: An anthem or psalm sung before the Communion service.
4. Any composition of vocal music appropriate to the opening of church services.
Source : Webster's Unabridged Dictionary, 1913