A period of three days (especially in Roman Catholic liturgy).(noun)
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Use "triduum" in a sentence
"The triduum, the three holiest days of the Christian year, begin on Maundy Thursday evening, and conclude with the Easter Vigil, which begins at sundown on Saturday evening -- the days being reckoned in the church's original way of reckoning: the Jewish calendar."
"Tomorrow morning, before entering the Easter triduum, but very closely tied to it, the "Messa Crismale" will take place in every diocese during which the bishop and priests of the diocese renew their promises made at ordination."
"Each year during the "holy triduum of Christ's crucifixion, death and resurrection," as St. Augustine calls it, the Church goes back over the final stages of Christ's life on earth in a climate of prayer and penitence: his being condemned to death, his journey to Calvary carrying the cross, the sacrifice he made for our salvation, and laying his body to rest."